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BY THE SAME AUTHOR. 

Dictionary of Electrical Words, Terms and Phrases, 

Third Edition. 669 double-column octavo pages, 

582 illustrations, - - - - - - $5°° 

Electricity and Magnetism. Being a Series of Ad- 
vanced Primers. 306 pages, 116 illustrations, - 1 00 

Electrical Measurements, and Other Advanced 

Primers of Electricity. 429 pages, 169 illustrations, 1 00 

The Electrical Transmission of Intelligence, and 
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THE W. J. JOHNSTON COMPANY, Ltd., 

:Put>li€*tLer€;, 
253 Broadway, New York. 






/ 



ELECTRICITY & 

ONE HUNDRED YEARS AGO 
AND TO-DAY. 



Ulitb Copious IHotcs anO Ertracts. 



/ 



uv 
EDWIN J. HOUSTON, Ph.D. (Princeton). 



I 

• :7 ' — 



NEW YORK : 
THE \V. J. JOHNSTON COMPANY, Ltd., 

253 B&OADWAY. 



Copyright, 1894, by 
THE W. J. JOHNSTON CO., Ltd. 



p t 



: : 




TO 

JAMES HAMBLETT, 

PF ESI DENT OF THE DEPARTMENT OF ELECTRICITY, 

BROOKLYN INSTITUTE OF ARTS AND SCIENCES, 

THIS LITTLE BOOK IS RESPECTFULLY 

DEDICATED BY THE AUTHOR. 



Philadelphia, May, 1894. 



PREFACE. 



This little book, "Electricity, One Hundred Years 
Ago and To-day," contains the text of a lecture 
delivered before the Electrical Section of the Brook- 
lyn Institute. In preparing the lecture for publi- 
cation, which I have determined to do in the belief 
that it may be of value to students of Electricity, I 
have concluded to permit the text to remain substan- 
tially as delivered, preferring to add, in the way of foot- 
notes, whatever additional matter may be required, 
rather than to materially change the original matter or 
arrangement. 

The wide scope of the lecture, which embraces the 
progress made by electric science practically from its 
birth to the present day, necessitated, from the limit 
of time of a single lecture, a much briefer treatment 
of many important diseu.- tnd inventions than 



IV PREFACE. 

seemed advisable when the lecture was put in book 
form. Various portions of the original lecture, have, 
therefore, been considerably extended by means of 
foot-notes. 

In tracing the effects produced by great discoveries 
or inventions, it has been deemed desirable to introduce 
copious extracts from the papers in which such discov- 
eries or inventions were originally described. In this 
manner only, can an intelligent conception be formed 
of the importance of a discovery, or the completeness 
of an invention. 

In some cases no little difficulty has been experi- 
enced in finding the exact publication in which the 
first description of a great discovery or invention was 
given. This, of course, is almost necessarily the case 
when the discovery or invention belongs to the type 
for which a number of rival claimants exist. A diffi- 
culty in such studies, arises, too, in readily attaining 
access to a sufficiently complete collection of works on 
the early literature of the science. I have been for- 
tunate, in this respect, to have had at my disposal the 
very excellent library of the Franklin Institute, in which 
is to be found, perhaps, the most complete collection of 
the Transactions and Proceedings of learned societies, 
and of the general and periodical scientific literature of 
the last century or so, that is to be found in this country. 

It will of course be understood, that no pretense is 
made in this little book, of doing any more than treat- 



PREFACE. V 

in the most general manner, some of the more in- 
teresting facts concern: - and 
inventions that may fairly be considered as creating 
epochs in the history of electrical progr ss. Many vol- 
umes would necessarily be required to give each of 
such disc - or inventions the treatment its impor- 
tar. dd require. 

In common with many others I have always, hith- 
erto, ascribed to Sir Humphrey Davy the honor of 
having first discovered the carbon voltaic arc. In en- 
deavoring to find the original publication in which this 
discovery is described, I found that Davy was antici- 
pated in the discovery by many others, the introduc- 
tion of whose names, together with the details that 
would be nee — in tracing the progress of so im- 
portant a discovery, would require a much greater space 
than I have at my command in this little book. 

The experiment most generally referred to at present 
and, indeed, in literature contemporaneous with the 
time of Davy, as being the first ever made with the 
carbon voltaic arc, was that made by Davy with a 
voltaic pile or battery of some two thousand couples 
the Royal Society of London. These ex- 
periments, however, differed only in degree, and not in 
character, from those performed by many others before 
the date of Davy's public experiments, and were 
merely the first in which the full splendors of the vol- 
light wer.e publicly demonstra: 



yj preface. 

The extracts from early writers have been made 
comparatively full, becanse of the difficulty most stu- 
dents experience in gaining access to the books or peri- 
odicals in which such publications first appeared. The 
extracts from publications concerning the more recent 
discoveries or inventions are less frequent, because 
such are either more generally known or more readily 
accessible. 

The plates from which the pages of this book are 
printed came into possession of the present publishers 
through the failure of the firm which had originally 
undertaken the publication of the work. As the typo- 
graphical execution falls short of the standard of the 
publishers with whose imprint it is now issued, it is but 
fair to relieve them, by this explanation, of responsibility 
for any typographical deficiencies that may be observed. 

Edwin J. Houston. 

Philadelphia, Central High School, 
May, 1894. 



ELECTRICITY, 

ONE HUNDRED YEARS AGO AND TO-DAY. 



KING SOLOMON speaking of his age, said, "There 
is nothing- new under the sun/' and King Solo- 
mon was qualified to judge, for he was learned 
far beyond any man of his time, and, possibly, beyond 
any man who came after him. 

There is a type of man who is apt to echo Solomon s 
judgment; not only, perchance, because he wishes this 
judgment to be true, but "also because it is a very rare 
case in which he cannot find facts sufficient to show 
reasonable grounds for such judgment. I allude to the 
scientific expert, whose zeal for his client, sometimes 
leads him to force facts, or to interpret by-gone records 
in the light of the knowledge of to-day. 

The much maligned expert, however, provided be 
adheres to facts, is as much justified in presenting the 
ible for his client as the lawyer, the 
clergyman, or any other special pleader. 



8 ELECTRICITY, 

To the superficial student of scientific progress, it 
may readily appear as if, in reality, there was nothing 
new under the sun ; that everything that is, has been. 
Let any student, however, once drink deeply at the 
fountain of scientific historical knowledge, and he will 
view the facts in a very different light. 

To assert that there is nothing new under the sun 
since the time of Solomon is to assert that the human 
mind has made no progress during that time; has 
undergone no development. Certainly no one can be 
found willing to make such a monstrous assertion. 

Our minds are cast after a common pattern, in sub- 
stantially the same mould. While in particular cases, 
we must necessarily admit the existence of finer tex- 
ture, of better hereditary peculiarities, of higher devel- 
opment, and of grander possibilities, yet, after all, 
thoughts conceived by one mind are apt to be com- 
mon to many, if not to the majority of minds. 

At certain times in the world's progress the environ- 
ment may cause so rapid a development of the germs 
of great ideas, the incentive to unusual effort may be so 
great, the necessity for a new combination of ideas so 
urgent, and the encouragement of an age ripe for the 
birth of such ideas, so marked, that substantially the 
same ideas may be conceived simultaneously in differ- 
ent parts of the world. 

At other times the peculiarities of the environment 
may be so unfavorable, the incentive to unusual effort 



ONE HUNDRED YEARS AGO AND TO-DAY. i) 

so small, the necessity for new ideas so apparently lim- 
ited, and the encouragement so feeble, that although 

the idea may be born, yet it may fail to meet with 
recognition by the world, and so be passed by and for- 
gotten, only, in some later, riper time to be again inde- 
pendently conceived and offered to the world. 

Ideas born out of time, like immature or unripe fruit, 
die an untimely death. A great idea is conceived in 
different parts of the world, by different brains, at times, 
often hundreds of years apart. The first producer of 
the idea is unnoticed, perhaps ridiculed, possibly perse- 
cuted, and the gift, freely offered to the world, is con- 
signed to oblivion until some historian of science again 
brings it to light ; while a later originator of the same 
idea is hailed by an applauding world, because such 
world has developed so far as to be able to appreciate 
the idea, and is in need of it ; and yet the earlier pro- 
pounder was probably intellectually greater than the later. 

Great ideas or inventions may be arranged under 
three types <>r classes, viz., — 

(i). Immature or incomplete. 

(2). Untimely and therefore unfruitful. 

(3). Fruitful because mature and timely. 

Immature or incomplete ideas or inventions produce 
but little influence on the world — at times, however, 
they are of great value because they tend to direct 
thought to certain channels and thus act as forerunners 
of greater and more valuable ideas. 



IO ELECTRICITY, 

Untimely ideas may be mature, but the times are unripe 
for them ; the condition of the environment unsuited ; 
and, therefore, though mature and complete in them- 
selves, yet like unripe fruit they are unfruitful and pro- 
duce no progeny for the development of the world. As 
a rule, the originators of such ideas or inventions belong 
to that limited class of men who are so far beyond their 
fellows, that the world is unable to understand them. 

Originators or inventors of this type of ideas are not 
apt to have contestants for priority of invention or 
origination. Their thoughts or inventions are apt to 
stand alone. They give their thoughts or inventions to 
an unready world, that fails to appreciate such thoughts 
or inventions, and immediately forgets them and rele- 
gates them to oblivion. 

Ideas or inventions, which are fruitful because mature 
and timely, are of far greater value to the world than 
those of the second type since they bear fruit almost 
immediately. It matters little to the world whether 
they have been conceived before or not. When prac- 
ticable, they almost necessarily find extended applica- 
tion because the times are ripe for them. 

The fact that such ideas are frequently found to be 
old does not prevent them from being original with 
their later producers. The latter, however, cannot 
claim to be the first originators of great ideas, nor can 
they justly claim a position in the class of the favored 
few who stand alone. 



ONE HUNDRED YEARS AGO AND TO-DAY. I I 

Ideas or inventions of the third type almost neces- 
sarily belong to a class and not to a favored few. 

Concerning the second type of ideas or inventions, 
there sometimes arises, though unfortunately for the 
world's progress very seldom, inventors whose genius 
is so great that although their ideas are born out of 
time, yet they are presented in such a matured form 
and so intelligently and completely worked out in 
that most valuable state of actual operation, that the 
world is forced, despite its indifference, to/eceive and 
employ them. Such geniuses, by their unusual abil- 
ities, get in advance of the world of thought and ac- 
tion and drag it up to their position of vantage. 

As to the third type of ideas or inventions, it almost 
invariably happens, when the world is ripe and waiting, 
that they are simultaneously made by different minds 
in different parts of the world, and it is this fact that 
has led the superficial to accept the belief expressed by 
Solomon of old. 

Prof. Youmans expresses a similar idea.* In his 
opinion, great ideas belong to eras rather than to indi- 
viduals. 

* The work of Prof. E. L. Youmans, above referred to, 
is "The Correlation and Conservation of Forces : A 
Series of Expositions by Prof. Grove, Prof. Helmholtz, 
Dr. Mayer, Dr. Faraday, Prof. Liebig and Dr. Carpen- 
ter." New York: D. Appleton and Company, 1883. On 
page XV. of the introduction, Prof. Youmans says,— 

" In the history of human affairs there is a growing concep- 



It ELECTRICITY, 

As the advance wave of intellectual progress moves 
towards the boundaries of the unknown, several investi- 
gators moving with that wave must, at very nearly the 
same time, discover new features and facts on the hori- 
zon beyond. At some times they see these from the 
same point of view, and more or less complete inven- 
tions simultaneously result. At other times several 
observers see an object from different points of view, 
and those partial and conflicting descriptions are given 
which lead to that inevitable scientific controversy 
which tends to renewed observation and more accu- 
rate description. 

The scientific historian who follows the advance of 

electrical progress and endeavors to note the positions 

tion of the action of general causes in the production of events, 
and a corresponding conviction that the part played by indi- 
viduals has been much exaggerated, and is far less controlling 
and permanent than has been hitherto supposed. So also in the 
history of science it is now acknowledged that the progress of 
discovery is much more independent of the labors of particular 
persons than has been formerly admitted. Great discoveries 
belong not so much to individuals as to humanity ; they are less 
inspirations of genius than births of eras. As there has been a 
definite intellectual progress, thought has necessarily been lim- 
ited to the subjects successively reached. Many minds have 
been thus occupied at the same time with similar ideas, and 
hence the simultaneous discoveries of independent inquirers, of 
which the history of science is so full. Thus at the close of the 
sixteenth century, philosophers had entered upon the investiga- 
tion of the laws of motion, and accordingly we find Galileo 
Benediti, and Piccolomini proving independently that all bodies 
fall to the earth with equal velocity, whatever their size or 
weight. A century after, when science had advanced to the 



A Hundred Years AGO and To-da\. 13 

attained by it at different eras, during the past one 
hundred years or so, will unquestionably find much 
that is of interest, much that is perplexing, hut nothing 
devoid of instruction. 

Let us then, with this historian, pass hurriedly over 
the path of the wave of electric progress and note the 
more important records left by it at different stages of 
its advance ; and, as we study its more important re- 
cords, let us compare them with corresponding- points 
in electrical progress during the present time, so as to 
assure ourselves whether such progress has been real 
or is only apparent. 

Following the three divisions of great ideas already 
referred to, viz., the immature, the untimely and the 

systematic application of the higher mathematics to general 
physics. Newton and Leibnitz discovered independently the dif- 
ferential calculus. A hundred years later questions of molecular 
physics and chemistry were reached, and oxygen was discovered 
simultaneously by Priestley and Scheele, and the composition of 
water by Cavendish and Watt. These discoveries were made 
,m- the periods were ripe for them, and we cannot doubt thai if 
who made them had never lived, the labors of others would have 
speedily attained the same results. The discoverer is, therefore, 
in a great degree, but the mouthpiece of his time. Some discern 
clearly what is dimly shadowed forth to many ; some work out 
the results more completely than others, and some seize the 
coming thought so long before it is developed in the general 
consciousness, that their announcements are unappreciated and 
unneeded. This view by no means robs the discoverer of his 
honors, but it enables us to place them upon a j aster estimate, 
and to pass a more enlightened judgment upon the rival claims 
which are constantly arising in the history of science. " 



14 ELECTRICITY, 

fruitful, let us start at the point of genesis of electric 
progress and examine that oft-reverted-to experiment 
of the Greek Thales.* 

* Thales occupies so prominent a place in the present 
world of electrical science, and so little is generally 
known of his attainments in other directions, that I have 
thought it well to quote a brief account of his life as 
given by Benj. Martin in a publication entitled "Biogra- 
phia Philosophica. " Being an account of the Lives, 
Writings, and Inventions, of the most eminent Philoso- 
phers and Mathematicians who have flourished from the 
Earliest Ages of the World to the present Time. By 
Benjamin Martin, London : Printed and sold by W. 
Owen, near Temple-Bar, and by the Author, at his 
House in Fleet-street. 1764. Page 1. 

"Thales was born, as the best Writers agree, in some Part of the 
35th Olympiad, nourished in the 50th, and died about the 58th ; 
the Interval between his Birth and public Appearance in Greece, 
was passed in Study, and Travels in various Parts of Asia, and 
into jEgypt ; in the former he acquired his first Insight into 
Astronomy, and, in the latter, his first Acquaintance with Geome- 
try, Mystical Divinity, and Natural Knowledge. Having finished 
his Studies abroad, he returned to his Native City, Miletus, and 
transported the Stock of Learning he had acquired into his own 
Country." 

" There are not any particular Circumstances mentioned in his 
History respecting significant Occurencies in his Travels, other 
than the Favour he met with from Amasis King of Mgypt, which 
Favour he lost by being too free in his Opinions concerning Kings: 
was, by such Freedom, obliged to leave the Country ; which was 
the probable Cause of his returning, at that Time, to Miletus." 

" In Miletus he lived for some Time as private as possible, de- 
voted to Study and Contemplation, and in instructing some few 
in the Learning he had acquired. These were Anaximander and 



A HUNDRED YKAKS Al'.O AND to-pay. 15 

It was not much, when viewed in the light of the world 

at its birth, some 600 B. C. ; merely a piece of amber 
rubbed against the clothing ; merely the gaining of a 
strange property ol first attracting and then repelling 
light objects Brought near it. 

It was. however, the birth of a great idea, an idea 

AnaximineS) both Natives of Miletus ; and afterwards Pythagoras, 

of what Country unknown, but usually called of Samas, so famed, 
as the Constitutor of the Italic Sect, and who assiduously pursued 
his Master's Steps, both in his Studies, and in his Travels." 

"Ili'tles, in this his Retirement, was courted by many, but cau- 
tiously avoided either attend ing, or receiving any Favours from 
them. He was often visited by Solon, and is said to have taken 
L^reat Pleasure in the Conversation of Thrasybulus, whose excel- 
lent Wit caused our Philosopher to forget that he was Tyrant of 
Miletus." 

"There nourished, at the same Time with him, six others, dis- 
tinguished by their singular Wisdom by their Morals, Rules, and 
Practice ; but the Epithet of Wise was given to Thales for his 
speculative Learning." 

44 Laertius. and with him various other Writers, agree, that lie 
was the Father of the Greek Philosophy, the first that made 
any Researches into natural Knowledge, or Enquiry into Mathe- 
matics." 

44 His Doctrine was, that W T ater, Moisture, or Humidity is the 
first Principle of natural Bodies, whereof they consist, and where- 
into they resolve ; and that God is the Mind, which formed all 
Things of Water.'' 

U 0I the World, he taught, there was but one, am" that made 

by God ; that it is disposed in due and regular Order, and that 
(iod animates the whole." 

"In Geometry he is said to have been an Inventor, as well as 
an Improver; a Science that had its Birth by Necessity in Mgypt^ 
where Thales acquired his primary Instruction, as Commeroe 
lir-t gave Being, by the like Necessity, to Number*." 

"lie. gave the ii:.-: Light into the Knowledge of soalenous, and 



t6 ELECTRICITY 

that unfortunately, for the world's progress, belonged 
to the class of immature ideas. Viewed in the light of 
to-day, its importance can hardly be over-estimated. It 
pointed out a terra incognita ; an unknown realm of phe- 
nomena that occupied nearly the entire domain of na- 
ture, and only waited patiently to be observed. It was 

other Triangles, many of which Euclid, has digested into his 
Elements ; but that for which he is more particularly celebrated, 
as being, according to Laerlius, his Invention, is what now ap- 
pears as the 47th Proposition of Euclid, That the Sums of the 
Squares of the two lesser Sides of a right angled Triangle is equal 
to the Square of the greater Side ; which is, however, disputed as 
the Invention of his Disciple Pythagoras. But all the Writers 
agree, that he was the first, even in JEgypt, who took the Height 
of the Pyramids by the Shadow, in the Manner the same is now 
usually effected, and therefore needs not any Illustration." 

"As an Astronomer, he divided the celestial Sphere into five 
Circles, or Zones, the Arctic, the Summer Tropic, the Equator, 
the Winter Tropic, and the Antartic Circle, placing the Zodiac 
under the three middle Circles, touching them all as it passes, 
and each of them cut in right Angles by the Meridian, that ex- 
tendeth from Pole to Pole ; Which have unjustly been ascribed 
to more modern Discoveries." 

"He first observed the apparent Diameter of the Sun, which 
he concluded to be the 720th part of the Circle or Zodiac, which 
he appears annually to describe about the Earth, which is divided 
into 360 Degrees ; and first discovered the Constellation of the 
lesser Bear." 

" He likewise first observed the Nature and Course of Eclipses, 
and calculated them to an Exactness ; one in particular, about 
the 50th Olympiad, memorably recorded by Herodotus, as it 
happened on a Day of Battle between the Medes, and Lydians, 
which, Laertes says, he had foretold to the Ionians. And the 
same Author informs us that he divided the Year into 365 Days ; 
but this Division he seems to have had from the ^Egyptians. 
Plutarch de placiU Philos, not only confirms his general Knowl- 



A HUNDRED TEARS AGO AND TO-DAY. 17 

like the sailing- of Columbus 011 that eventful voyage 

which resulted in the discovery of the Continent of the 
Future. 

But the idea was incomplete, the world was either 
skeptical or unable to understand the true significance 
of the phenomenon, or to appreciate the vast treasures 

edge of Eclipses, but that his Doctrine was, that an Eclipse of 
the Sun is occasioned by the Intervention of tli3 Moon, as may 
be seen in a Bason of Water, or Looking-glass ; and that an 
eclipse of the Moon is caused by the Intervention of the Earth.'' 

'"The Writers of his Life agree, that he was addicted to judi- 
cial Astrology; and Tully thinks there is something in that Sci- 
ence, and of his Acquaintance therc-with, which he aims to con- 
linn by the following Story:" 

"That Tholes being upbraided for his Poverty, resulting from 
the Study of Science, and foreseeing by his Skill in Astrology, 
there would be a Plenty of Olives that Year, he purchased all the 
Gardens about Miletus and Chios, and thus having acquired a 
Monopoly, disposed of them again at high Prices, and then told 
his Neighbours, that it was very easy for Men of Learning to be 
rich if they chose it, but that Wealth was not their Aim." 

"Laertius, and some others, agree with Tully in his Notion of 
this being an Astrological Prediction, which is fat from being a 
clear Point : It is sufficient, that he was capable of making a 
good Judgment of the approaching Season, and that it would be 
BUCD a Season, as wherein Olives are usually most plentiful. This, 
however, sufficiently evinces, that he had more worldly Wit than 
Us Neighbours conceived, when he thought proper to employ it ; 
U i- the Case <>f most Studious Men, when they turn their Atten- 
tion that Way. and affect the Object, as by Study they acquire a 
Sagacity and Penetration not common to the In attentive : But, 
as Self-interest i- t lie ruling Passion of our Natures, Men turned 
only to tie- Attainment of Wealth, will, with some EteaSOn, -mile 
at those who reduce themselves to Poverty, in Order to make 
others learned. " 



i8 



ELECTRICITY, 



of knowledge it was ready to unlock. Now that a riper 
world has availed itself of this first experiment in elec- 

"It is a sufficient Illustration of the Wisdom of Thales, that 
he was the Inventor, or Improver, in many Branches of useful 
Knowledge ; and whether right or wrong in his Contempt of Wealth, 
his Sagacity in other Respects superior to most Men." 

"His Morals were as just, as his Mathematics well grounded, 
pnd his Judgment in civil Affairs equal to either ; so that his 
Knowledge was as general, as the Good of Mankind his Care ; 
and as we have given a brief account of his Skill in Science, it 
may not be amiss to give here a concise Taste of his Morals, 
summed up in a few Lines." 

"Fear e'er thou sin, thyself, thd* none be nigh, 
Life fades, a glorious Death can never die ; 
Let not thy Tongue discover thy Intent, 
'Tts Misery to dread, and not prevent. 
He helps his Foes that justly reprehends ; 
He that unjustly praiseih, harms his Friends ; 
That 's not enough, that to Excess extends" 
"fie was very averse to Tyranny, and esteemed Monarchy 
little better in any Shape ; he was used to say, That a Tyrant, 
who chuseth rather to command Slaves than Freemen, is like an 
Husbandman who preferreth the gathering of Locusts and 
catching Fowls, to the reaping of Corn." 

" Concerning his Writings, it remains doubtful whether he left 
any behind him. Augustine mentions some Books of Natural 
Philosophy ; Simplicius, some written on Nautic Astrology ; Laer- 
tius, two Treatises on the Tropics and Equinoxes ; and' Suidas, a 
Treatise on Meteors, written in Verse." 

"His Death happened in Point of Time as is said above;the 
Occasion appears to have been his attending the Olympic Games, 
where, opprest with Heat, Thirst, and the Weakness of his Years, 
he, in public View, sunk into the Arms of his Friends." 

" He was buried, according to his own Appointment, in an ob- 
scure part of the Milesian Fields, where he predicted in future 
Times their Forum should be." 



A HUNDRED YEARS AGO AND TO-DAY. 1 9 

tricity. it seems to have boon a very easy thing to unfold 
one general principle in electric science after another, 
but, like the problem of Columbus as how to balance an 

egg on one end, it was quite simple only after it was 
once done, and the way pointed out. 

Thales' original experiment bore no fruit until sev- 
eral thousand years had passed. It is true that Theo- 
phrastus* some three hundred years after the time of 
Thales showed that some species of tourmaline when 

It is a significant fact that the Historian of Thales, 

writing as he did in 1764, left out in the various ac- 
counts he gave of the life work of this remarkable man, 
that particular observation concerning the properties 
acquired by rubbed amber, which in our own day has 

again brought Thales' name so frequently into the rec- 
ords of electrical investigations. 

♦Theophrastus flourished about 300 years before Christ. 
In his work on precious stones he asserts that amber 
possesses the same property of attracting light bodies 
that lyncurium does, which, he says, ''Attracts not 
only straws and small pieces of sticks, but even thin 
pieces of copper and iron."' 

The lyncurium here referred to is believed to be a 
variety of tourmaline, since all the properties described 
by Theophrastus as being p 1 by it are poss< 

by tourmaline. For example, that lyncurium v 
for seals, was pellucid, was of a deep red color, re- 
quired no small labor to polish and was endowed by 
friction with an attracting power like am! 



20 ELECTRICITY, 

rubbed, acquired similar properties to amber but the 
world was still unappreciative, and again allowed gold- 
en opportunity to pass by. 

It seems strange from our standpoint of to-day, that 
the existence of the electric force could have remained 
for so long a time unrecognized. It was certainly not 
for the want of acute minds. The Egyptians, the 
Greeks, or the Romans were in many respects as intel- 
lectually developed as any of the earth's present cul- 
tured races. The road leading into the unknown do- 
main of electric science was pointed out to them, but 
this road was neglected and soon forgotten, and, only 
during the past one hundred years or so, became the 
great thoroughfare of scientific progress. 

In thinking over the lapse of time during which the 
electric force remained unnoticed, though the way was 
pointed out, the probability has often occurred to me 
that in our own time the world is on the eve of the 
great discovery of some new and hitherto unrecognized 
force connected with the phenomena of thought or 
mental activity. It may be that the unprecedentedly 
rapid advance made by the wave of scientific progress 
is hurrying us nearer and nearer to the recognition of 
this force and of other forces that are undreamt of in 
our modern philosophy. 

Too often is the cry "cui bono" raised when some 
apparently trifling physical phenomenon is first re- 
corded. Because its place among other natural phe- 



A HUNDRED TEARS AND TO-DAY. ?T 

nomena has not yet been clearly pointed out, it is 
apt to be regarded as insignificant. I do not doubt but 
that those friends and acquaintance- 
whom he first showed his great experiment, I 
him in the light of a harmless enth --ibly, 

attributed approaching senility to one willing to in- 
dulge in such childish experiments : and yet, the utility 
of the experiment was probably it, if no: 

than that of any subsequent experiment ever tried in the 
wide domain of physical scien. 

Examining Thales original experiment in the light of 
to-day, we should carefully avoid forming the fol- 
lowing hasty conclusions : — 

That all the forces of nature have been discov- 
ered. 

(2). That any correctly recorded natural phenom- 
enon though apparently trivial is of no value to the 
world. 

I do not purpose, however, tracing the 
tricity from the time of Thales until now. That 
would require much more time than is placed at my 

- l! to-night. We are now i: 
ing the knowledg ssess an Is 

out one hundred years ago, and in com- 
paring and contrasting it with our present kno 
I say about one hundn vish 

to hamper our inv 

• thousand years t' 



2 2 ELECTRICITY, 

was permitted to slumber, and it was not until towards 
the close of the sixteenth century that Dr. Gilbert, phy- 
sician to Queen Elizabeth, extended the observation of 
Theophrastus and showed that many bodies besides am- 
ber and tourmaline, when subjected to friction, acquire 
the strange property of first attracting and then repel- 
ling light bodies brought near them. 

Gilbert published his observations in the year 1600, 
in a book called " De Magne/e." * He divided bodies 
into two great classes, electrics or those which could be 

*Dr. Joseph Priestley, in a work published in two vol- 
umes in London, in 1775, entitled, — "The History and 
Present State of Electricity, with Original Experiments," 
in alluding to the fact that Gilbert greatly extended the 
list of substances that could be electrified by friction 
says, on page 2, of Vol. I, 

" The attractive nature of amber is occasionally mentioned by- 
Pliny, and other later naturalists ; particularly by Gaffendus, Kenelm 
Digby, and Sir Thomas Brown ; but excepting the electricity of 
the substance called jet the discovery of which was very late 
(though I have not been able to find its author) no advances were 
made in electricity till the subject was undertaken by William 
Gilbert, a native of Colchester, and a physician at London ; who, 
in his excellent Latin treatise de magncte, published in the year 
1600, relates a great variety of electrical experiments. Consider- 
ing the time in which this author wrote, and how little was known 
of the subject before him, His discoveries may be justly deemed 
considerable, though they appear trifling when compared with 
those which have been made since his time." 

" To him we owe a great augmentation of the list of electric 
bodies, as also of the bodies on which electrics can act ; and he 
has carefully noted several capital circumstances relating to the 



A HUNDRED TEARS AGO AND TO-DAY. 

electrified by friction, and non-electrics or hich 

could not be so electrii >n is 

now known to be ' >n an erroneous idea, since 

bodies like the metals, whi duct electricity, are 

ified by friction as are n on-con du 
like glass or resin. If conductors be held in the ha 
as Gilbert held them when end I e the 

electric force by friction, they will at once sarily 

lose their electric charge icharge through the I 

of the experimenter to the earth. If, however, the; 



manner of their action, though his theory of electricity 
imperfect, as might be expected." 

liBEB and jet were, as I observed before, the only subst 
which, before the time of Gilbert, were known to have the prop- 
erty of attracting light bodies when rubbed ; but he found the 
same property in the diamoi 'hyst, 

I 
that g -cially that which is clear and transparent, has the 

same property : likewise all factitit 

y, he conclud su noes with 

su/pli :um lac tinged with various 

; iii J roch - cUunu Etorin, be 

*his property but in a 
mentioned -u! only when the air was char and free from 

•ire." 
•• ALT. * " :arr»-d Ui 

but all metals, all kinds of w« :1 ; in 

-olid, and the object of our - lat he im- 

1 that air. nV .1 all matter whirh was 

:u<»k»-, 
. but that whirh 



24 ELECTRICITY, 

insulated in any suitable manner, they are, as we all 
know, as readily electrified by friction as any other 
bodies. 

It may be interesting to inquire what mental qualifica- 
tions Gilbert possessed which permitted him to be prac- 
tically the first man after a lapse of some two thousand 
years to extend Thales' original observation. I think 
the answer is evident. The reason is to be found not so 
much in the higher mental development of Gilbert, 
although he was unquestionably possessed of a very 
remarkable intellect, but is to be found rather in his 
methods. 

Gilbert, who was born in 1540, flourished about the 
same time as Bacon, who was born in 1561. Before the 
time of Bacon, as you are probably aware, the inductive 
method of studying natural phenomena was almost un- 
known. The early observers, especially those belong- 
ing to the school of Greece, instead of endeavoring to 
ascertain the causes of natural phenomena by question- 
ing nature through experiments, and reasoning out nat- 
ural causes from the results of such experiments, as- 
signed for the phenomena fanciful causes and reasons 
which necessarily obscured the truth. * Bacon taught a 

* In an introduction to an "Account of Lord Bacon s 
Novum Organon Scientiarum, ,, published in London 
in 1827, in a serial publication entitled the " Library of 
Useful Knowledge," the following brief outline of 
Bacon's system of philosophy is given on page 8 ; 



A HlNDRFn YKAKS AGO ANP TO-RW. 2J 

system of Philosophy called Inductive Philosophy, in 
which the causes of phenomena are determined by 
careful experimentation and the facts obtained from one 
set of series ot experiments used as the basis of subse- 
E nt experiments. (See note on p. 24.) 

" It was reserved, however, for Francis Bacon. Lord Yerulam, 
to break the spell of the mighty enchanter of sStagira. and to give 
A final blow to the scholastic philosophy: — to make one grand 
and general attempt to deliver men's minds from the bondage of 
two thousand years ; —to assert the right of that reason with 
which the beneficent Creator has endowed man. as above all au- 
thority merely human ; — and to sketch the outlines of one grand 
and comprehensive plan, that suouid include in it the endleaa 
v rieties of our knowledge, and guide our inquiries in every 
branch. Born in the year 1561, and earl) entered as a student at 
Trinity College. Cambridge, this great genius soon began to feel 
istied with the vagueness and uncertainty of the existing 
of knowledge, the want of connexion between the sciences 
and the arts, and the consequent uselessness of the reigning spec- 
, ulations as regarded the purposes of life. The more he thought 
on the subject, the more he was convinced of the vanity of the 
scholastic learning of the times, and of the necessity of a thorough 
:nation in the method of treating the knowledge of nature, 
by laying aside all conclusions not founded on observation and 
experiment. He saw plainly that a great part of the evil lay in 
the extensive intluence which Aristotle still possessed in the 
schools; that u tture and /<* -t were neglected for the study of his 
ines, which were the arbiters in all disputes : the properties 
of matter, and the laws of motion, by which all effects are pro- 
6 l"-t in useless distinctions and dry definitions : the 
ra of the mind were exhausted in grave trilling and solemn 
: and the real advancement of human knowledge was al- 
peless, so long as such a state of things prevailed* A 

» earlier, the contests about nanus, and form*, and 

essences, were sometimes more ><-ri<>us than a mere strife of 

they end* d in actual bloodshed ; while the desputants 



26 ELECTRICITY, 

Passing over a considerable lapse of years from the 
time of Gilbert, I would briefly call your attention to 

took the side either of Occam, " the most subtil" or Duns Scotus 
" the invincible" the famous champions of the day ; and if the din 
of this philosopical, or rather imphilosopical war now raged no 
longer, — if those imposing titles were not now heard which had 
formerly been bestowed on the leader of rival parties, such as 
the most prof ound, the marvellous, the perspicuous, the irrefragable, 
the most resolute, the angelical, the seraphic doctor, — it was that all 
inquiry had well nigh ceased, and the minds of men were cast, 
with a very few exceptions, into a profound slumber, and filled 
only with the romantic visions of an imaginary philosophy. — Such 
had been the state of things at the time of Lord Bacon, and the 
brief notice we have taken of it may serve to throw light on the 
real value of his labours, which had for their object the establish- 
ment of a philosophy that is in fac L . no other than the philosophy 
of reason and common sense, in opposition to all mere theory 
and fancy, and to all impositions." 

" Under these circumstances Bacon wrote his Organon. His 
qualification for this bold attempt to clear the barren wastes of 
science, and to sow the seeds of a new creation of useful knowl- 
edge, will be best seen by studying his doctrines. We shall, 
therefore, now proceed to give an account of this most important 
and considerable part of his general work, the Instauratio Magna, 
or Instauration of the Sciences, Its title was probably suggested 
by Aristotle's Organon, containing his Logic ; it is called Novum 
Orjanon Sc'entiarun, or a New Method of Studying the Sciences, 
from the Greek word organon, which signifies an instrument or 
machine. The grand principle which characterizes this great 
work, and by the proper use of which its author proposes the 
advancement of all kinds of knowledge, is the principle of Induc- 
tion, which means, literally, a bringing in ; for the plan it unfolds 
is that of investigating nature, and inquiring after truth, not 
by reasoning upon mere conjectures about nature's laws and 
properties, as philosophers had been too much accustomed to do 
before, but by bringing together, carefully and patiently, a variety 
of particular facts and instances ; viewing these in all possible 



A HUNDRED YEARS AGO AND TO-DAY. 

Stephen Grey,* who, in 1729, first pointed out the dis- 
tinction between conductors and non-conductors of 

electricity. 

lights ; and drawing, from a comparison of the whole, some gen- 
eral principle or truth that applies to all. The foundation of 
this philosophy lies, in short, in the history of naJture itself in 

making a laborious collection of the facts relating to any one 
subject of inquiry, previously to any attempt at forming a 
system or theory. Actual experiment, which Bacon significantly 
terms " asking questions of nature,*' must be resorted to, where 
experiments, as in chemistry, can be made; observations mnsl 
be accurately collected, in the subjects proper to these, as rfs- 
tronomy ; and conclusions are, in all cases, to be drawn only 
from what is actually witnessed, after the comparison of a suffi- 
cient number of facts, and a due regard to objections. In hie 
treatment of this important subject of Induction, a new and 
more rational employment of the faculties is exhibited than the 
wor'd had ever seen; and never before was there laid down to 
the minds of men the true theory of investigating all truth, 
whether natural or moral ; indeed, Bacon has well merited the 
appellation he has received — the Prophet of the Arts, and the 
Father of Experimental Philosophy." 

Proceeding on so sound a basis as this, an investi- 
gator, possessed of the powerful intellect of Gilbert, was 
necessarily soon far advanced into this hitherto undis- 
covered domain of science. I will not ask you to fol- 
low me in his many researches, but will refer you for a 
fuller description of the same to his work " De Mag- 
nete, " already referred to. See note in Appendix. 

* In Dr. Joseph Priestley's work on the " History and 

Present State of Electricity/' already referred to, thus 

ribes on page 32, of Vol. I., the labors of Stephen 

y in the domain of electricity. 

" Am Kit this long interval, oommenoea a new era in the history 



28 ELECTRICITY, 

The fact now so well known to us of the eno.rmous 
rapidity with which electrical effects, produced at one 
end of a line wire or conductor, are manifested at the 
other end, which may be hundreds or even thousands 
of miles distant, naturally excited considerable Wonder 
at the time it was first discovered, and it is not at all 

of electricity ; in which we shall have the works of another 
labourer in this new field of philosophy to contemplate, viz., Mr. 
Stephen Grey, a pensioner at the Charter House. No person 
who ever applied to this study was more assiduous in making 
experiments, or had his heart more entirely in the work. This 
will appear by the prodigious number of experiments he made, 
and some considerable discoveries with which his perseverance 
was crowned ; as well as by the self-deceptions, to which his pas- 
sionate fondness for new discoveries exposed him." 

At this time Grey had conducted numerous experiments 
on the conducting powers of different substances, and 
had succeeded in passing an electric discharge down- 
wards through a suspended pack thread. He also ex- 
perimented on the ability of hempen threads horizon- 
tally supported to carry discharges. In order to sup- 
port these lines he suspended them by means of fine 
silken threads which he believed prevented the elec- 
tricity from escaping because they were thin. He 
afterwards discovered that this action depended on 
their non-conducting power for the discharge rather 
than on their small diameter. His remarks concerning 
these- results we find on page 40 of Priestley's work 
above quoted. 

" In the same manner in which silk was found to be a non-con- 
ductor, it is probable that, about the same time, hair, rosin, 
glass, and perhaps some other electric substances, were found to 
have the same property, though the discovery be no where 



A HUNDRED YEARS AGO AM) TO-DAY. 20, 

surprising, that even at this very early date, some hints 
were thrown out as to means whereby the electric force 
could be utilized for the purposes of telegraphic commu- 
nication. Such suggestions we find made by numerous 
writers and, indeed, some actually tried the experiment. 
Among these I may mention Watson.* who, in 1747 

particularly mentioned : for we shall presently iind Mr. Grey 
making use of them to iusulate the bodies which he electrified." 

••AFTER this, Mr. Grey and his friend amused themselves 
with trying how large surfaces might be impregnated with the 
electric effluvia ; electrifying a large map, table cloth, <fcc. They 
also carried the electric virtue several ways at the same time, 
and to a considerable distance each way." 

"THE magnetic effluvia, they found, did not in the least inter- 
fere with the electric ; for when they had electrified the load 
stone, with a key hanging to it, they both attracted leaf brass like 
other substance-." 

* ''William Watson in a communication to the Royal 
Society of London in 1747, refers to the ability of 
electricity to pass through circuits or lines of substances 
non-electrical in character. By non-electrical circuits 
Watson referred to substances like conductors which 
could not (as he thought) be electrified by friction. In 
Vol. X. of the Abridged Philosophical Transactions. 011 
page 347, he says : 

u In the paper I did myself the honour some time ago to com- 
municate to the Royal S>><-irfi/, [ took notice, that, among the 
many surprising properties of Electricity, none was more 
remarkable, than that the electrical power, accumulated in any 
non-electric matter contained in a glass phial, described apOD 
[ plosion a circuit through any line of BUbstances non-elect ri- 
eal in a considerable degree ; if one end thereof was in contact 
with tip- external sorfaoe <»f this phial, and the other end upon 

the explosion touched either the electrified gun-barrel, to which 



30 ELECTRICITY, 

erected various conducting lines which extended for 
distances of several miles and used the earth as a 
return. In sending, electricity through these lines Wat- 



the phial in charging was usually connected, or the iron hook 
always fitted therein. This circuit, where the non-electric sub- 
stances, which happen to be between the outside of the phial and 
it's hook, conduct Electricity equally well, is always described in 
the shortest manner possible ; but if they conduct differently, 
this circuit is always formed through the best conductor, how 
great soever it's length is, rather than through one which con- 
ducts not so well, though of much less extent." 

" It has been found, that in proportion as bodies are suscepti- 
ble of having Electricity excited in them by friction, in that pro- 
portion they are less lit to conduct it to other bodies ; in conse- 
quence whereof, of all the substances we are acquainted with, 
metals conduct best the electrical powers ; for which reason the 
circuit before spoken of is formed through them the most readily. 
Water likewise is an admirable conductor ; for the electrical 
power makes no difference between solids and fluids as such, but 
only as they are non-electric matter." 

The electrified gun-barrel referred to was connected 
to the electrical machine and was provided with an iron 
hook on which was hung a Leyden phial. Under these 
circumstances, it will be seen that the Leyden phial was 
discharged through the conducting circuit. 

On page 357, of the publication above referred to, 
, Watson describes an experiment made concerning the 
passage of an electrical discharge through a conducting 
path as follows : — 

" The electrifying machine being placed up one pair of the 
stairs in the house at Highbury -bam, a wire from the coated phial 
was conducted upon dry sticks as before, to that station by the 
side of the New River, which was to the northward of the house. 
The length of this wire was 3 furlongs and 6 chains, or 2376 feet. 
Another wire fastened to the iron bar, with which, in making the 



A HUNDRED YEARS AGO AND TO-DAY. 3 1 

son employed the discharge oi a Leyden phial which 
had then been two years invented. In order to deter- 
mine whether or not the electric shocks had been trans- 
explosion, the gnu-barrel was touched, was conducted in Like man- 
ner to the station upon the New River to the southward of the house. 
The length of this wire was 4 furlongs 5 chains and 2 poles, or 
3003 feet The Length oi both wires, exclusive of their turnings 
round the sticks, was 1 mile, 1 chain, and 2 poles, or 5879 feet. 
For the more conveniently describing the experiments made here, 
we will call the station to the northward I), and the other E. 

At this distance the gentlemen proposed to try, first, whether 
or no the electrical commotion was perceptible, ll both the ob- 
servers at D and E, supported by originally-electrics, touched the 
conducting wire with one hand, and the water of thereto River 
with an iron rod held in the other ? Secondly, whether or no that 
commotion was perceptible, if the observer at E, being in all re- 
spects as before, the observer at D, standing upon wax, took his 
rod out of the water ? Thirdly, whether or no that commotion 
perceptible to both observers, if the observer at 1). was placed 
upon wax and touched the ground with his iron rod in a dry 
gravelly field at least 300 yards from the water : 

" As from the situation of the ground, trees, dbc. neither of the 
stations could be seen by each other, or by the observer at the 
electrifying machine, it was agreed to discharge a gun as a signal 
to get ready, and to do the same, as near as might be, half a 
minute before each explosion." 

"In these experiments, as well as the former, the coated phial 

ich time charged as high as it could bo ; SO that if the dif- 

a to the observer- was considerable, it was 

other causes more than to the phial's being differently 

electrified." 

On page 364 of the same publication Watson draws 
the following conclusions from these experiments ; viz., 
"From a review of these experiments the following observa- 
leduced. 

I. That, in ail the preceding operations, when the wires have 



32 ELECTRTCITY, 

mitted, observers were placed at different parts of the 
line who received the shocks through their bodies. It is 
needless to remark that telegraphic receiving instru- 
ments of this character would be extremel) r unsatisfac- 
tory in practice. 

been properly conducted, the electrical commotions from the 
charged phial have been very considerable only, when the ob- 
servers at the extremities of the wire have touched some substance 
readily conducting Electricity with some part of their bodies. 

II. That the electrical commotion is always felt most sensibly 
in those parts of the bodies of the observers, which are between 
the conducting wires, and the nearest and most non-electric sub- 
stance ; or in other words, so much of their bodies, as comes 
within the electrical circuit. 

III. That, upon these considerations, we infer, that the elec- 
trical power is conducted between these observers by any non- 
electric substances, which happen to be situated between them, 
and contribute to form the electrical circuit. 

IV. That the electrical commotion has been perceptible to 2 
or more observers at considerable distances from each other, 
even as far as 2 miles. 

V. That when the observers have been shocked at the end of 2 
miles of wire, we infer, that the electrical circuit is 4 miles ; viz. 
2 miles of wire, and the space of 2 miles of the non-electric mat- 
ter between the observers, whether it be water, earth, or both. 

VI. That the electrical commotion is equally strong whether 
it be conducted by water or dry ground. 

VIE. That if the wires between the electrifying machine and 
the observers are conducted upon dry sticks, or other substances 
non-electric in a slight degree only, the effects of the electrical 
powers are much greater than when the wires in their progress 
touch the ground, moist vegetables, or other substances in a great 
degree non- electric. 

VIII. That by comparing the respective velocities of Elec- 
tricity, and sound, that of Electricity, in any of the distances yet 
experienced, is nearly instantaneous." 



A HUNDRED YFARS AGO AND TO DAY, 



33 



In the same connection should be mentioned Dr, 
Franklin,* who, in 1748, set fire to spirits of wine by 

a current of electricity sent across the Schuylkill River, 
using: the river and earth as a return circuit. These 



* Concerning Franklin's original experiment of trans- 
mitting an electric shock across the Schuylkill and 
tiring- spirits of wine thereby, the following description 
is given by Franklin on page 37, of a work entitled 
•' Experiments and Observations on Electricity, made 
at Philadelphia in America by Benjamin Franklin, 
L.L.D. and F. R.S. published in London in 1 769 as 
follows : — ■ 

k * Chagrined a little that we have been hitherto able to produce 
nothing in the way of use to mankind; and the hot weather eom- 
>n, when electrical experiments are not so agreeable, it is 
proposed to put an end to them for this season, somewhat humor- 
ously, in a party of pleasure, on the Banks of the Skuylkil.* 
Spirits, at the same time, are to be fired by a spark sent from Bide 
to side through the river, without any other conductor than the 
water: an experiment which we some time since performed, to 
the amazement of many.t A turkey is to be killed for our dinner 
by the electrical shock, and roasted by the electrical jack, before a 
fire kindled by the electrical bottle; when the healths of all famous 
electricians in England, Holland, France and rmany, are to be 
drank in electrified bumpers^ under the discharge of guns from 
the electrical battery." 

• 'The river that washes one side of Philadelphia, as the 
]) laware does the other; both are ornamented with the sum- 
mer habitations of the citizens, and the agreeable mansions 
of the principal people of this colony." 

f**As the possibility of this experiment has not been easily 
conceived, I shall here describe it. — Two iron rods, about 
three feet long, were planted just within the margin of the 
river, on the Opposite side-. A thick piece of wire, with a 
small round knob at its end. was fixed to the top of one of 



34 ELECTRICITY, 

early forerunners of the telegraph belonged to inven- 
tions of the immature type and necessarily died with- 
out bearing fruit. 
Naturally enough about this time interest began to 

the rods, bending downwards, so as to deliver commodiously 
the spark upon the surface of the spirit. A small wire fast- 
ened by one end to the handle of the spoon, containing the 
spirit, was carried a-cross the river, and supported in the air 
by the rope commonly used to hold by, in drawing the ferry 
boats over. The other end of this wire was tied round the 
coating of the bottle ; which being charged, the spark was 
delivered from the hook to the top of the rod standing in the 
water on that side. At the same instant the rod on the other 
side delivered a spark into the spoon, and fired the spirit. 
The electric fire returning to the coating of the bottle, 
through the handle of the spoon and the supported wire con- 
nected with them." 

"That the electric fire thus actually passes through the water, 
has been satisfactorily demonstrated to many by an experi- 
ment of Mr. Kinnerfley's, performed in a trough of water 
about ten feet long. The hand being placed uuder water in 
the direction of the spark (which always takes the straight 
or shortest course) is struck and penetrated by it as it 
passes." 

J "An electrified bumper is a small thin glass tumbler, near 
filled with wine, and electrified as the bottle. This when 
brought to the lips gives a shock, if the party be close shaved, 
and does not breathe on the liquor." 

The above humorous description given by Frank- 
lin of this informal electric club will, I feel sure, remind 
my readers of the various electrical meetings of a some- 
what similar character that have been held quite re- 
cently in cities not far from the "City of Brotherly 
Love. " 



A HUNDRED YEARS AGO AND TO-DAY. 



55 



be manifested concerning the cause of the curious 

force, that appeared to be able to SO readily transmit 
its manifestations through the densest metallic sub- 
stances with such incredible rapidity. Various hypoth- 



It has interested me no little to obtain some further 
description concerning the aforesaid turkey, that was in 
those early days as Franklin says "killed" but as we 
unfortunately now say'Vleetroeuted." 1 have found a 
further description concerning this early electrocution 
in a letter to Mr. Collinson on page 209, of Vol. XLVII, 
ot Philosophical Transaetions published in a paper read 
before the Royal Society on June 6th, 1751. 

M As Mr. Franklin, in a letter to Mr. Collinson some time since, 
mentioned his intending to try the power of a very strong elec- 
trical shock upon a turkey, I desired Mr. Collinson to let Mr. 
Franklin know, that I should be glad to be acquainted with 
the result of that experiment. He accordingly has been so very 
obliging aa to send an account of it, which is to the following 
purpose. He made first several experiments on fowls, and 
found, that two large thin glass jars gilt, holding each about six 
gallons, and such as I mentioned I had employed in my Last 
paper I laid before you upon this subject, were sufficient, when 
fully charged, to kill common hens outright ; but the turkeys, 
though thrown into violent convulsions, and then, lyi: 
dead for some minutes, would recover in Less than a quarter 
of an hour. However, having added three oilier such to the 
former two, though not fully charged, he killed a turkey of about 
ten pounds weight, and believes that they would have killed a 
much larger. He conceited, as himself says, that the birds kill'd 
in this manner eat uncommonly tender. 

"In inir. experiments, lie found, that a man could. 

without great detriment, bear a much greater shock than he 

imagined: for he inadvertently received the stroke of two of 

jar- through his arm- and body when they were very near 

full j charged. I- to him an universal blow throughout 



36 ELECTRICITY, 

eses were framed to account for its origin. I will call 
your attention to but two of the most famous of these 
hypotheses; viz., the double fluid hypothesis of Du 
Fay,* and the single fluid hypothesis of Franklin. 



the body from head to foot, and was followed by a violent quick 
trembling in the trunk, which went gradually off in a few seconds. 
It was some minutes before he could recollect his thoughts, so as 
to know what was the matter ; for he did not see the flash, tho' 
his eye was on the spot of the prime conductor, from whence it 
struck the back of his hand ; nor did he hear the crack, tho' 
the bystanders said it was a loud one ; nor did he particularly 
feel the stroke on his hand, tho' he afterwards found it had 
raised a swelling there of a bigness of half a swanshot, or pistol- 
bullet. His arms and the back of his neck felt somewhat 
numbed the remainder of the evening, and his breast was sore 
for a week after, as if he had been bruised. From this experi- 
ment may be seen the danger, even under the greatest caution, 
to the operator, when making these experiments with large jars ; 
for it is not to be doubted, but that several of these fully 
charged would as certainly, by increasing them, in proportion to 
the size, kill a man, as they before did the turkey." 

"Upon the who'e, Mr. Franklin appears in the work before us 
to be a very able and ingenious man ; that he has a head to con- 
ceive, and a hand to carry into execution, whatever he thinks 
may conduce to enlighten the subject-matter, of which he is 
treating : and altho' there are in this work some few opinions, 
in which I cannot perfectly agree with him, I think scare any- 
body is better acquainted with the subject of electricity than 
himself.'' 

*Du Fay's hypothesis of two electric fluids naturally 
came to him when he discovered the existence of two 
distinct kinds of electricity, the vitreous, or that pro- 
duced by friction on rubbing glass, and the resinous, 
or that obtained from friction on rubbing resin. 






A HUNDRED YEARS AGO AND TO-DAY, 3J 

The double fluid hypothesis of electricity of Du Fay 
taught as follows 

(i). That the phenomena of electricity are due to the 
cuce oi two hypothetical, imponderable fluids that 

are respectively positive ami negative. 

(2). That the particles oi each o\ these fluids are 
mutually repellant : that is that the particles of the 
positive fluid repel other particles of the positive fluid ; 

and, similarly, the particles of the negative fluid repel 
other particles of the negative fluid. 

(3). That the particles of the opposite fluids are 

mutually attractive ; that is that the particles of the 

tive fluid attract the particles of the negative fluid 

and vice versa ; and, that when they so attract they 

combine and neutralize each other's effects. 

(4). That these two fluids arc both attracted by mat- 
ter, and that they are present in all kinds of matter, in 
a masked or neutralized condition. 

That the act of electrification by friction or other 
cause, consists in a separation of the two opposite 

Priestley in the work before referred to speaks thus in 
V<>:. II.. on page 1 7 : 

"WHEN Mr. Da Fay discovered the two opposite species of 
electricity, which he termed the vitreous and resinous electricity, 
he necc--arilv formed the idea of tun distinct electric fluids, repul- 
.ith respect to themselves, and attractive of one another. 
But he had no idea of both species being actually concerned in 
electrical operation, and that glass or rosic alone always 
produced them both. This theory, therefore, was as simple in 
its application as the other.* 1 



38 ELECTRICITY, 

fluids, the positive fluid going to, say, the body rubbed 
and the negative fluid to the rubber. 

(6). That the phenomena of electricity are produced 
by ihe tendency of the two opposite fluids to recom- 
bine and neutralize each other. 

The single fluid hypothesis of Franklin* explains 

* Franklin thus describes his electrical hypothesis in 
a letter to Peter Collinson, Esq., written in Philadel- 
phia, July nth, 1747. — Quoted by Jared Sparks on 
page 185, of Vol. V. of his work entitled "The Works 
of Benjamin Franklin containing Several Political and 
Historical Tracts not included in any Former Edition, 
and many Letters Official and private not Hitherto 
Public." 

" But now I need only mention some particulars not hinted in 
that piece, with our reasonings thereupon ; though perhaps the 
latter might well enough be spared." 

" 1. A person standing on wax, and rubbing the tube, and an- 
other person on wax drawing the fire, they will both of them 
(provided they do not stand so as to touch one another) appear 
to be electrized, to a person standing on the floor ; that is, he 
will perceive a spark on approaching each of them with his 
knuckle." 

"2. But, if the persons on wax touch one another during the 
exciting of the tube, neither of them will appear to be elec- 
trized." 

" 3. If they touch one another after exciting the tube, and 
drawing the fire as aforesaid, there will be a stronger spark be- 
tween them, than was between either of them and the person on 
the floor." 

"4. After siich strong spark, neither of them discover any 
electricity." 

" These appearances we attempt to account for thus* We sup- 



A HUNDRED TEARS AGO AM) ID-DAY. 

trical phenomena by the following assumptions: 

{i). That the phenomena of electricity are due to 
the presence o( a single imponderable fluid. 

(2). That the particles ol this fluid are mutually re- 
pellant 



as aforesaid, that electrical fire i> a common element, «>t 
which every one of the three persona above mentioned has his 

equal share, before any operation is begun with the tube. A. who 
stands on wax and rubs the tube, collects the electrical tire from 
himself into the glass ; and. his communication with the eoinmon 
stoek being cnt oil by the wax. his body is not again immediately 
supplied. B, (who stands on wax Likewise) passing his knuckle 
along near the tube, reeeives the fire which was collected by the 

from A : and his communication with the common stock 
being likewise cut off. he retains the additional quantity received. 

standing on the floor, both appear to be electrized : for 
he, having only the middle quantity of electrical tire, receives 
a -park upon approaching B, who has an over quantity ; but 

one to A. who has an under quantity. It A and B ap- 
proach to touch each other, the spark is Btronger, because the 
difference between them is greater. After such touch there is no 
spark between either of them and C. because the electrical lire in 
all is reduced to the original equality. If they touch while elee 
trizing. the equality is never destroyed, the fire only circulating. 
•■ have arisen some new terms among us : we say B (and 
bodies like circumstanced) is electrized positively : A. negatively. 
Or rather. B U I. A:ul we daily in our 

experime: ~ :/e bodies pl\ 1 us, as we think pr< 

'1 o electr:. .0 more needs to be known than this, 

that the parts of the tube or sphere that are to be rubbed) do, in 
the instant of the friction, attract the electrical lire, and therefore 
dng rubbing ; the same parts immediately, as 

the fr: • » ^ r ive the fir«- they 

]y that has !' 98. 1 I OS yon may circulate 
\vn ; you D I BUb1 ract 

it, upon or from any t>< that body with the 



40 ELECTRICITY, 

(3). That the particles of this fluid are attracted by- 
all kinds of matter. 

(4). That all kinds of matter contain a certain quan- 
tity of the electrical fluid ; that when this quantity is 
present in any body no electrical effects are manifested, 

rubber, or with the receiver, the communication with the common 
stock being cut off. We think that ingenious gentleman was 
deceived, when he imagined (in his Sequel), that the electrical fire 
came down the wire from the ceiling to the gun-barrel, thence to 
the sphere, and so electrized the machine and the men turning 
the wheel, <fcc. We suppose it was driven off, and not brought on 
through that wire ; and that the machine and man, &c, were 
electrized minus, that is, has less electrical fire in them than 
things in common." 

About this time a hypothesis was framed by Abbe Nollet 
which endeavored to explain the causes of electrical 
phenomena and which attracted considerable attention. 
This hypothesis belonged to the type of hypotheses of 
two separate fluids or streams. A description of Nollet's 
hypothesis is thus given on page 384, of Vol. X, of the 
Philosophical Transactions of the Royal Society : 

" I am not only satisfied of the existence of an effluent electric 
matter, which all the world allows, and which shews itself 1000 
ways ; but many convincing reasons have also assured me, that 
there is, round every electrified body, an affluent matter, which 
comes to it not only from the ambient air, but likewise from 
all the other bodies, whether solid or fluid, that are round 
about, and within a certain distance of it. If these sur- 
rounding bodies are of a simple nature, as a stone, a piece 
of iron, &c nothing issues from them but pure electrical 
matter : but if they are animals, plants or fruits, or, in a word, 
any organized bodies, or such, in me pores of svhich there is any 
substance capable of giving way to the impulses of the electric 
matter ; this matter will, in issuing forth with the great rapidity, 



A HUNDRED YEARS AGO AND TO-DAY. 4 I 

but, that if such body possesses either a surplus or a 
deficit of the fluid, it manifests electrical excitement 

(5). That positive electrification is due to an excess 
of the fluid, and negative electrification to a deficit 

Although neither of these hypotheses are accepted at 
the present day, yet they are conyenient for explaining 
many electrical phenomena ; and, even at the present 
day are so frequently alluded to in electrical literature 
that I have thought it well to mention them. 

These hypotheses account very well for the funda- 

which it is known to have, carry along with it whatever it finds 
moveable enough to be displaced by it ; and by so much will the 
weight of the body be diminished ; the s me effect being lure 
produced by the affluent matter, as is produced on electrified 
bodies by the effluent. If you will please to read over my essay, 
what I advance will be better understood. The increase or dim- 
inution of perspiration is not a matter of indifference to the 
animal oeconomy : this <new method of increasing it at will may 
possibly prove of use ; it is neither inconvenient nor dangerous ; 
and neither I myself, nor any body else of those on whom I made 
my experiments, suffered even the least inconveniency from it. 
One feels neither motion nor heat differing from that of the natural 
state. Nor did the animals give any signs of uneasinex, while 
they were electrifying : a little wearniness, and a better appetite, 
were the only effects ever perceived." 

In applying his hypothesis to the explanation of the 

phenomena of eleetrieity, Nollet asserted that these two 
opposite effluvia were thrown in opposite directions. 
In order to avoid the difficulty in explaining why these 

streams failed to interfere with one another, he 
inled the existence in all matter of t 
one set where the effluvia came out of the elect 
body and another set where it entered it. 






4-2 ELECTRICITY, 

mental fact that when electricity is produced by friction, 
or, indeed, by any other means, the production is in- 
variably of a dual character, as much negative elec- 
tricity being produced as positive. This, of course, 
would necessarily follow from either hypothesis. 

According to the double fluid hypothesis the excite- 
ment is due to the separation of two opposite electrici- 
ties, the amount of positive electricity liberated will 
necessarily be sufficient in amount to exactly neutralize 
the negative electricity. 

According to the single fluid hypothesis, the surplus 
obtained on one body by the act of friction must neces- 
sarily equal the deficit left on the other body. 

1745 was a memorable year in the history of elec- 
trical progress ; for, it was in this year that Von Kleist, 
Dean of the Kathedral of Comin in Pomerania, made 
the discovery of the Leyden Jar. 

If you will endeavor to recall the excitement produced 
in both scientific and financial circles throughout the 
world generally, by any one of the more notable achieve- 
ments in electricity during the past ten or fifteen years, 
say, for example, the successful production of the incan- 
descent electric light, or the invention of the telephone 
or the phonograph, you may, perhaps, be able to form 
some idea of the intense excitement produced in 1745, 
by the discovery of the Leyden jar or vial. 



\ 



A HUNDRED HEARS AGO AND TO- PAY. 

The times were ripe for this discovery. The atten- 
tion of investigators in different :' the world was 
directed to the electrical force. The invention o[ the 

len jar therefore belonged to the type of fruitful 
inventions, and natural 1 .} h we find several claim- 

ants for its first conception. As far as 1 have been 
to trace original records, it would - first 

'very was made by Von Kleist,* in 1745, al- 

* Priestley attributes the discovery of the Leyden jar 
or Phial, as it was then called, to Von Kleist, who com- 
municated the discovery in a letter to Dr. Lieberkuhn 
above referred to. Von Kleist erroi eved 

that part ot the force of the phial is contributed to it by 
the human body. In the letter from which the above 
quotation (p. 44) is taken we find the following: 

"A TIN tube, or a man, placed upon electrics, is electrified 
much stronger by this means than in the common way. When I 

:it this phial and nail to a tin tube, which I have. fifte* n 
long, nothing but experience can make a person believe h«>w 
strongly it is electrified. I am persuaded, he adds. that, in this 
manner, Mr. Boze would not have taken a second electrical 
Two thin _ iave been broken by the shock of it. I 

vtraordinary. that when this phial and nail are 

atact with either conducting or non-condncti r, the 

strong shock does not follow. I have cemented it to wood, metal. 

Ling-wax, tic. when I Km Lfiod without any j 

The human body, there! Dthing 

pinion is confirmed by 1 1 that, on] 

the phial in my hand, I cannot fire spiriU with it . " 

The n phial tak< m the fact that 

a native of Leyden, independ 
Lerful powers in accumulati tricity b; 

.3 whik tig some iments with 



44 ELECTRICITY, 

though both Muschenbroeck and Cunseus of Leyden 
also claim it. 

Von Kleist describes his discovery in a letter to Dr. 
Lieberkuhn of Berlin, dated Nov. 4th, 1745, and read by 
him to the Academy of Science, in Berlin. I will quote 
from this letter from Vol. I, p. 103, of Priestley's book: 

"When a nail, or a piece of thick brass wire, &c. is 

Muschenbroeck and Allamand, Professors in the Uni- 
versity of Leyden. For this reason the discovery is 
frequently referred to as having been made by Muschen- 
broeck, or by Cunaeus. In a communication to the 
Royal Society made on October 30th, 1746, and pub- 
lished in volume X., of the Philosophical Transactions, 
on page 296, Watson thus refers to Muschenbroeck's ex- 
periments : 

" I now proceed to take notice of that surprising effect, that 
extraordinary accumulation of the electrical power in a phial of 
water, first discover d by Professor Musschenbroek, a man born to 
penetrate into the deepest mysteries of Philosophy : and I hope 
I shall stand excused, if I enter into a minute detail of the cir- 
cumstances relating thereto. The experiment is, that a phial of 
water is suspended to a gun-barrel by a wire let down a few 
inches into the water through the cork ; and this gun-barrel, sus- 
pended in silk lines, is applied so near an excited glass globe, 
that some metallic fringes inserted into the gun-barrel touch the 
globe in motion. Under these circumstances a man grasps the 
phial with one hand, and touches the gun-barrel with a finger 
of the other. Upon which he receives a violent shock through 
both his arms, especially at his elbows and wrists, and across 
his breast. This experiment succeeds best, cceteris paribus. 

1. When the air is dry. 

2. When the phial containing the water is of the thinnest glass. 

3. When the outside of the phial is perfectly dry. 

4. In proportion to the number of points of non-electric con- 



A HINDRED Y'KAKS M.O AM) TO-DAY. 4> 

put into a small apothecary's phial and electrified, re- 
markable effects follow ; the phial must he very dry, or 
warm. 1 commonly rub it over beforehand with a lin- 
ger, on which I put some pounded chalk. If a little 
mercury, or a few drops of spirit of wine, be put into it, 
the experiment succeeds the better. As soon as this 
phial and nail are removed from the electrifying glass, 

tact. Thus if you hold the phial only with your thumb and 
tinker the snap is small ; larger when you apply another finger, 
and increases in proportion to the grasp of your whole hand. 

5. When the water in the phial is heated : which being then 
warmer than the circumambient air, may not occasion the 
condensing the floating vapour therein upon the surface of the 
}_'lass. 

From these considerations it is to be observ'd, that this effect 
arises from electrifying the non-electric water, included in the 
originally - electric glass; so that whatever tends to make the 
outside of the glass non-electric by wetting it, as, a moist hand, 
damp air, or the water from the inside of the phial, defeats the 
experiment, by preventing the requisite accumulation of the 
electrical power." 

M That a gun-barrel is absolutely necessary to make this experi- 
ment succeed, is imaginary ; a solid piece of metal of any form 
is equally useful. Nor have I yet found, that the >troke is in 
[»r< 'portion to the quantity of electrified matter ; having observed 
the stroke from a sword as violent as that from a gun-barrel with 
ral excited iron bars* in contact with it." 

k * I have tried the effect of increasing the quantity of water in 

- of different sizes, as high as four gallons, without in the 

increasing the stroke. If tilings of iron are substituted in 

torn of water, the effect is considerably lessened* If mercury, 

much the game as water : the stroke i- by qo mean- increased in 

proportion to their specific gravities, as might have been 

y 

''The phial should not be lees than can conveniently i»« grasped 



46 ELECTRICITY, 

or the prime conductor, to which it hath been exposed, 
is taken away, it throws out a pencil of flame so long, 
that, with this burning machine in my hand, I have 
taken above sixty steps, in walking about my room. 
When it is electrified strongly, I can take it into another 
room, and there fire spirits of wine with it. If while 
it is electrifying, I put my finger, or a piece of gold, 

I generally make use of those, which hold seven or eight ounces, 
and fill them about four-fifths with water ; and the stroke from 
one of these, under the same circumstances, is equally strong 
with that of a Florence flask held in the hand, which I have some- 
times made use of ; though the glass of this last is equally thin 
with that of the phial, and the quantity of water four times as 
much. That the stroke therefore is not as the quantity of water 
electrified, is evident from this experiment. This fact does not 
depend on my judgment alone, but likewise upon the opinions 
of several learned Members of this Society, who have experienced 
the greater and less quantity of water." 

* If of six men touching each other, and standing upon 
originally-eleotrics, one touches the gun barrel, the whole are 
electrified ; all these then must be consider'd, as so much 
excited non-electric matter. From the aggregate of all 
these, not more fire is visible upon the touch than from 
either of them singly. 

"f" In this experiment, and in others, wherein we assert, that 

the stroke is not increased in proportion to the quantity of 

electrified matter ; it must always be understood, that the 

excited non electrics themselves are touched, without being 

contained in originally-electrics, as water in the glass ; for 

otherwise (as will hereafter be specified) the effects of different 

quantities of matter will be very different." 

The comparatively little that was understood at this 

early date concerning the action of the Leyden jar, as is 

revealed in the above remarks regarding the size of the 

jar, etc^ is too evident to need comment. 



A HUNDRED YEARS AGO AND l<> DAY; } 7 

which I hold in my hand, to the nail, [• receive a shock 

which stuns my arms and shoulders. " 

The most extravagant assertions were made con- 
cerning the physiological effects produced by the dis- 
charge of the Leydenjar. 

In an account given by Cunseus in a letter to Reau- 
mur he describes the effects produced on him by the 
discharge as follows : 

During the excitement throughout the world of letters, 
generally produced by the discovery of the Leyden jar, 

numerous experiments were made concerning the rase 
with which its discharg-e could pass through a great 
number of people. Early experiments of this character 
are described in Vol. X. of the Philosophical Transac- 
tions, on page 333, thus 

"When the phial has been sufficiently electrified as above, the 
whole company join hands ; the operator at one extremity of the 
line grasps the bottom of the electrified phial, and the person at 
the other extremity touches the wire, which rises above the cork. 
At that instant, the whole company receives a shock, resembling 
that in the experiment of the gun-barrel, but not so strong : for 
it -.cms noc at all to extend beyond the elbows." 

"This is tlif experiment, which abbe* Nollei performed upon 

f the guards, before the king, who were all so sensible of it 

at the same instant of time, that the surprize caused them all to 

spring up at once ; as it will indee I force any person to do that 

subjects himself to the trial; though the convulsionary motion 

it-elf, as I observed before, reaches not beyond the elbows: but 

:• or lesser effect depend entirely upon the longer <»r 

ber application of the phial to the electrifying speroid ; and 

I am credibly informed, that when due precautions have nol 

in thia particular, some per. -on- have received Mich violent 
hav< benumbed, and Impaired, to a certain di 



48 ELECTRICITY, 

" I lost my breath, and it was two days before I re- 
covered from the effects of the blow and terror." He 
adds, "I would not take a second shock for the King- 
dom of France." 

Another experimenter asserts : 

" That he lost the use of his breath for some minutes 
and then followed so intense a pain along his right arm 
that he feared permanent injury therefrom." 

Still another asserts, that "he suffered great convul- 
sions through his body : that it put his blood in agita- 
tion ; that he feared an ardent fever and was obliged to 
have recourse to cooling medicines." 

the use of their arms for a day or two, before they perfectly re- 
covered themselves. I can assure you, however, from my own 
experience, that, with the precautions I have already taken 
notice of, there is no manner of danger, though at the same time 
a sufficient efficacy may bo communicated to the phial, to gratify 
any one's curiosity : and in this particular I have been the more 
prolix, lest any bad consequences should happen to the unex- 
perienced." 

A similar experiment which was tried at the Convent 
of the Carthusians in Paris, is thus described on page 
335— 

" At the grand convent of the Carthusians here in Paris, the 
whole community formed a line of 900 toises, by means of iron 
wires of a proportionable length, between every 2 ; aud, con- 
sequently, far exceeding the line of the 180 of the guards above- 
mentioned. The effect was, that when the two extremities of 
this long lino met in contact with the electrified phial, the whole 
company, at the same instant of time, gave a sudden spring, and 
all equally felt the shock, that was the consequence of the exper- 
iment." 



A HUNDRED TEARS AGO AND TO-DAY, 4Q 

From what we know of the typos of electrical ma- 
chines at this early time, and the character ol the Ley- 
den jars that were constructed, it is evident that the 
shocks obtained by these early experimenters must 
Seen of an exceedingly trivial character.* 

* Note for example the following description of an ex- 
periment made by Prof. Allamand with a Leyden phial 
made from an ordinary beer ^lass as quoted from Vol. X, 

of the Philosophical Transactions on page 321. 

*• There is an experiment that Mr. V Allamand has tried ; ho 
electrified a tin tube, by means of a glass globe ; he then took in 
his left hand a <^lass full of water, in which was dipped the end 
of a wire ; the other end of this wire touched the electrified tin 
tube : He then touched, with a linger of his right hand, the elec- 
trified tube, and drew a spark from it, when at the same instant 
he felt a most violent shock all over his body. The pain has not 
been always equally sharp, but he says, that the first time he losl 
the use of his breath for some moments ; and he then felt so in- 
tense a pain all along his right arm, that he at first apprehended 
ill consequences from it ; tho' it soon went off without incon- 
venience." 

" It is to be remarked, that in this experiment lie stood simply upon 
th»- floor, and n<>t upon the cakes of resin. It does n<>t Bucceed with 
all L r lass<-s. and tho' lie has tried several, lie has had perfei I success with 
none but those <»t Bohemia. He has tried English glass* - without any 
effect. That glass with which it best succeeded was a !»• 61 glafcS." 

Or the following experiment made by Professor Mus- 
schenbroeck, as described on the same page of the above 

publication : 

"Mr. M>< > ck the professor has repeated his expert] 

holding in his hand a hollow bowl exceeding thin, full <>f v. 
and he say- he experienced a mosl terrible pain. Be Bays, the 

glass mubt not be at all wet on the outride," 



50 ELECTRICITY 

I often amuse myself when reading an early account 
of an important discovery in science, by endeavoring to 
place myself in the position of the experimenter, and 
by entering as far as possible into his hopes and ideas, 
to picture the effects that he expects to obtain from his 
experiments. I can readily imagine this early experi- 
menter reasoning somewhat as follows : 

"How can I obtain a bottle full of this strange fluid, 
and, by thus isolating it, study its properties just as I 
would those of any other fluid? Since glass is a non- 
conductor, I will place some conducting fluid inside a 
glass bottle, and will lead the electricity from an electri- 
cal machine through a conductor to the inside of this 
bottle. As soon as I then obtain a bottle full of the fluid, 
I will remove it from the machine, examine its properties 
and thus get at its effects." 

This is practically what Cunseus did ; he placed some 
water in a small phial, and, passing a bent nail down 
through the cork into the liquid, hung the apparatus on 
the prime conductor of an electrical machine. As the 
apparatus was probably crudely made he steadied it 
while turning the machine, by holding the phial in his 
hand. On the charging of the phial, the water formed 
the inside coating, and his hand the outside coating, 
and he thus obtained, as he thought, a bottle full of 
electricity. Stopping the machine he then lifted the 
phial from the prime conductor, grasping it by the bent 



A HUNDRED TEARS AGO AND TO-DAY, £1 

nail and in this way effected the discharge. lie did, 
' at its " and was unquesl 

r his eriment 
In :. >e on electricity, published in 1795 in three 

velun Tiberius which by the way gi 

perhaps, the tin s1 c unplete account 

cal scici time oi its publica- 

tion, some idea maj mate pla 

at this time on the importance of the discovery of the 
Ley den jar. 

"I shall in general" Cavallo remarks, "only ol 
that although the science had, through the indefatigable 
tion of many ingenious persons, and by the 
that were daily produced, excited the curr 
of philosophers, and engaged their attention ; yet, as the 
E anything, whether great or small, known or 
unknown, are seldom much attended to. if their effects 
-triking and singula ctricity had, till the 

studied by none but Philos< It> 

11 could in part be imitated by a loadstone; its 
light by phosphorous : and, in nothing contrib- 

ctricity the subject of pub" tion, 

and a general cu until the d 

the v umulation of its rs, in what is com- 

monly called th •'<//, which was accidentally 

made in the year 1745. Then, and not till then, did 
the study tricity become gen very 

beholder, and invited to the I Electrician 



52 ELECTRICITY, 

greater number of spectators, than were before assem- 
bled together to observe any philosophical experiments 
whatever." 

" Since the time of this discovery, the prodigious 
number of electricians, experiments, and new facts that 
have been daily produced, from every corner of Europe, 
and other parts of the world, is almost incredible. Dis- 
coveries crouded upon discoveries ; improvements upon 
improvements ; and the science ever since that time 
went on with so rapid a course, and is now spreading 
so amazingly fast, that it seems as if the subject would 
soon be exhausted, and electricians arrive at an end of 
their researches ; but, however, the ne plus ultra is, in 
all probability, as yet at a great distance, and the young 
electrician has a vast field before him, highly deserving 
his attention, and promising further discoveries, per- 
haps, equally, or more important than those already 
made. " 

Before leaving the history of electric progress just be- 
fore the time of the discovery of the Leyden jar, I can 
hardly give a better idea of the actual state of the 
science than by the following extract read before the 
Royal Society by Dr. J. T. Desaguliers in January, 
1 74 1, as quoted from Vol. VIII, page 430, of the Philo- 
sophical Transactions. 

" About a year or two ago, in a Paper I gave in to the Roijal Society, 
I endeavored to establish some general Principles concerning 
Electricity, from the Consideration of many Experiments, which 
have been tried by others, as well as some new Experiments by 



A HUNDRED YEAR? AGO AND TO-DAY. ~ } 

So much for the Leyden phial at the time of its dis- 
ry. It is a curious fact that some of the most im- 
portant advances in the science oi electricity, during 

:". an Account of which I tl. 3 - I shall OOlj 

now repeat my Distinction of all Bodies into two I D re- 

ef Electricity, and make good the Definitions that I gave by 
some further Experiments : and though I do not pretend to know 
the Cause of Electricity in general, yet I hope from a few I 
of Electricity, deduced from Phanomena^ to solve most other 
omena, (though seeming quite unaccountable) so far as 
they shew what Law of Electricity they depend upon ; and to be 
able to foretel what will happen to most bodies before the Ex- 
periments are tried upon them in an electrical way." 

1. "Bodies electric per se are such in whom a virtue of at- 
tracting and repelling small Bodies at a distance is inherent, 
_h it is not always in Action, so as to produce that Effect. 
But by rubbing, patting with the Hand, hammering, warming, 
and sometimes only exposing to dry Air, such Bodies exert the 
Virtue above-mentioned; otherwise they are in a Non-electric 
Star 

_ Non-electric Bodies are such that no electrical Virtue can be 
excited by any Action upon the Bodies themselves, - rub- 

warming, dbc. But an Electric when excited, can 

communis .-electric, and that Virtue will be 

red by all the Part- Non-electric, (be the Bo I 

long or large) and be as it were, collect 

that End of * i>-ctric. which is farthest from the Place 

Electricity :- served." 

\»n-electr: g received Electricity, will communi- 

c Body brought to touch it, or only brought pretty 
and that often with a sna: 

■ by that Means all it's own Elect ri i' 
4. •* An Elect ric per se will become a N ' ric for a time, if it 

be ma 1 become receptiv< . which it 

will receive re :. and carry to the other, where 

tricity wi with a -mall Explosion, to in 

oth» 



54 ELECTRICITY, 

recent times, have been made in the direction of the 
Leyden phial. I refer especially to the researches of 
Nikola Tcsla and Elihu Thomson, on the effects 
produced by rapidly alternating discharges at high 
potential. 

5. " An Electric per se, in which Electricity is excited, may be- 
come Non-electric by being exposed to moist Air, whose humid 
Vapour it attracts ; and then, brought to the Fire, or into very dry 
Air, recover it's Electricity when the Moisture is exhaled again." 

6. "An Electric per se may be made strongly Electric in Part 
of it's Length, whilst the other part remains in a Non-electric 
State." 

7. " A Body in a State of Electricity (whether a Non-electric hav- 
ing received Electricity, or an Electric per se, excited to Elec- 
tricity) will attract all Non-electrics, and repel other Bodies that 
are in a State of Electricity, provided the Electricity be of the 
same kind." 

8 "A Non-electric Body will not retain the Electricity which it 
receives from an Electric per se, unless it be free from touching 
any other Non-electric body ; but must be suspended or sup- 
ported by Electrics per se touching only them and the Air." 

9. " An Electric per se, when it is not reduced to a Non-electric 
State, will not receive Electricity from another Electric per se, 
whose Electricity is excited, so as to run along it's whole Length ; 
but will only receive it a little Way, being (as it were) saturated 
with it." 

10. "An Electric per se will not lose it's Electricity at once, 
but only the Electricity of such Parts of the Body as have com- 
municated it to other Bodies, or near which Non-electrics have 
been brought." 

11. " When a Non-electric, which has received Electricity, com- 
municates it's Electricity to another, it loses all it's Electricity 
at once ; and the Effluvia, in coming out, strikes the new Body 
brought near, as well as the Body first made electric." 

12. "Excited Electricity exerts itself in a Sphere around the 



A HUNDRED TEARS AGO AND TO-DAY, 55 

Perhaps one of the most important electrical inves- 
tigations that has been made in recent years is that o( 
Nikola Tesla* concerning the effects produced by dis- 
charges of alternating currents oi high potential at extra- 
ordinary frequencies. Tesla has shown by a scries of 

Eleotrio per se ; or rather a Cylinder if the Body be eylindric." 

13, "The Electricity which a Non-electric of great Length (foi 
Example, a hempen string 800 or 900 Feet long) receives, runs 
from one End to the other in a Sphere of electrical Hffluvia; 
But all the supports of this String must be Electrics per se. n 

14. "If this String be branched out into many Strings, the 
Electricity will run to all their Ends." 

1"). "If the Non-electric String, which is to receive and carry 

on the electric Effluvia, be not continuous, but has between it's 

Ends some Electrics per se, the Effluvia, will Btop at the first of 

them, unless the Interruption or Discontinuation of the Non- 

ric be short." 

♦The experiments of Tesla are of such recent date that 
hardly necessary to append but brief extracts con- 
cerning them. That I should do so at all is only on 
ount of their exceeding novelty and value. 
Entering, as Tesla did, into a domain of electrical 
which was apparently thoroughly explored, he 
showed, by the light of his genius, that it was 
>st unknown region. He has shown, for example. 
that our ideas of the conducting and non-conducting 
ordinary matter for electrical discharges oi 
moderate frequencies, must be entirely changed for the 
employed by him. To such dischar 
»me absolute non-conductors, and e 
• ordinarily termed non-condui 
luct the discharges with marked facility. Then 



56 ELECTRICITY, 



experiments which are unique both for their complete- 
ness and scope, that, for discharges of enormous fre- 
quency, ordinary conductors become absolutely non- 
conductors, while such substances as vulcanite and 

again as regards the physiological effects of alternating 
discharges Tesla shows that at the enormous frequencies 
which it may be possible to give such discharges, they 
may lose their deadly character and become rather like 
the genial sunshine. 

In a lecture delivered before the American Institute of 
Electrical Engineers at Columbia College on the 20th of 
May, 1891, and published in Vol. VIII. , Nos. 6 ancf 7 
of the Transactions of the American Institute of Electri- 
cal Engineers, on page 2jj y Tesla describes a variety of 
discharges obtained by the use of high frequencies of 
alternation as follows : 

"First, one may observe a weak, sensitivo discharge in the 
form of a thin feebled-colored thread. (Fig. 4.) It always 00- 







Fig. 4. —Sensitive Thread 
Discharge. 
curs when, the number of alternations per second being nigh, the 
current through the primary is very small. In spite of the ex- 
cessively small current, the rate of change is great and the differ- 
ence of potential at the terminals of the secondary is therefore 
considerable, so that the arc is established at great distances ; 



A HTNDRED YEAKS 

ordinary currents possess 1 
f insulation, 
charges. He has proved that the phys 

. I than 

but the quantity of "electricitj - * in motion > cant, 

barely sufficient to maintain a thin, thread-li^e arc. It is exces- 
sively sensitive and may be made so to such a degree that the 
mere act of breathing near the coil will atfect it. and unless it is 
perfectly well protected from currents of air. it wriggles around 

tntlj. NeYertheless, it is in this form • 
ent, and when the terminals are e-third of 

Tiking dista: it only with difficulty. 

i rsisteney, when - > the 

arc being excessively thin: presenting, therefore, a very small 
surface to the blast. I*- gn -ensitiveness. when very long, is 
probably due to the motion of the particles of dust suspended in 
the air.*' 

:.en the current through the primary is increased the 
charge gets broader an 

of the coil becomes visible until, finally, under proper cond: 
a white flaming arc _ n as thick as one's fingec and 




r IQ. 5. -r l-AMING 1 E. 

striki: _• Inoed. T -nark- 

able heat, and 
the h: : .vhirh ac 

• ie a shock from the coil under would not 



58 ELECTRICITY, 

constant currents, or of alternating currents of but 
moderate frequency. 

But what is more interesting about these experiments 
is their possible commercial bearing. Tesla has pro- 
be advisable, although under different conditions, the potential 
being much higher, a shock from the coil may be taken with im- 
punity. To produce this kind of discharge the number of alter- 
nations per second must not be too great for the coil used ; and, 
generally speaking, certain relations between capacity, self in- 
duction and frequency must be observed. " 

Then again on page 279, 

" When the flaming discharge occurs, the conditions are evi- 
dently such that the greatest current is made to flow through the 
circuit. These conditions may be attained by varying the fre- 
quency within wide limits, but the highest frequency at which 
the flaming arc can still be produced determines, for a given 
primary current, the maximum striking distance of the coil. 
In the flaming discharge, the eclat effect of the capacity is 
not perceptible. The rate at which the energy is being stored 
then just equals the rate at which it can be disposed of through 
the circuit. This kind of a discharge is the severest test for a 
coil ; the break, when it occurs, is of the nature of that in an 
overcharged Leyden jar. To give a rough approximation, I 
would state that with an ordinary coil, of say 10,000 ohms resist- 
ance, the most powerful arc would be produced with about 12,000 
alternations per second." 

"When the frequency is increased beyond that rate, the poten- 
tial of course rises, but the striking distance may nevertheless 
diminish, paradoxical as it may seem. As the potential rises, the 
coil attains more and more the properties of a static machine, 
until, finally, one may observe the beautiful phenomena of the 
streaming discharge, Fig. 6, which may be produced across the 
whole length of the coil. At that stage, streams begin to issue 
freely from all points and projections. These streams will also 
be seen to pass in abundance in the space between the primary 



A HUNDRED TEARS AGO AND rO-DAY. -o 

duced lamps on the principle of bombardment in vac- 
uous spaces, as well as in spaces filled with air at 
ordinary pressures. lie has lighted incandescent lamps 
one terminal only of which was connected to the source 

and the insulating tube. When the potential 1- i rot — ively high, 
they will always appear, even if the frequency be low, and even if 



Fig. 6.— Streaming Discharge. 

the primary be surrounded by as much as an inch of wax, hard 
rubber, glass or any other insulating substance. This limits 
greatly the output of the coil, but I will later show how I have 
been able to overcome to a considerable extent this disadyai 
in the ordinary coil." 

"Besides the potential, the intensity of the streams depends on 
the frequency ; but if the coil be very large they show then- 
no matter how low the frequencies used. For instance, in a very 
large coil of resistance of 67,000 ohms, constructed by me 
time ago, they appear with as low as 100 altcrnati* leoond 

and less, the insulation of the secondary b» ing :5 4 inch of ebonite. 
When very intense, they pr dace a QOJ ;r to ihat produced 

b charging of aHoltz machine, but m v.rfnl.and 

they emit a strong smell ol y. the 

more apt they are to suddenly injure the coiL With excessively 
frequencies, they may without producing any 

an to h 1 uniformly." 

•• I ae • . ■ '-"Ti 

struct to permit of one's seeing 



60 ELECTRICITY, 

of alternating current. He has even lighted such lamps 
when their terminals were not connected by any con- 
ductor with such source. Indeed, the investigations 
made by this acute observer has almost opened a new 
science within that comparatively new science of elec- 
tricity. 

through the tube surrounding the primary, and the latter should 
be easily exchangeable, or else the space between the primary 
and the secondary should be completely filled up with insulating 
materials, so as to exclude all air. The non-observance of this 
simple rule in the construction of commercial coils, is responsible 
for the destruction of many an expensive coil." 

"At the stage when the steaming discharge occurs, or with 
somewhat higher frequencies, one may by approaching the ter- 
minals considerably and regulating properly the effect of capacity, 
produce a veritable spray of small silver-white sparks or a bunch 
of excessively thin silvery threads (Fig. 7^ amidst a powerful 




Fig. 7.— Brush and Spray 
Discharge. 

brush — each spark or thread possibly corresponding to one alter- 
nation. This, when produced under proper conditions, is probably 
the most beautiful discharge, and when an air blast is directed 
against it, it presents a singular appearance. The spray of 
sparks, when received through the body, causes some inconven- 
ience, whereas when the discharge simply streams, nothing at all 
is likely to be felt if large conducting objects are held in the 
hands to protect them from receiving small burns.'' 



A HUNDRED YEARS AGO AM) TO-PW. 6 1 

An exceedingly important discovery concerning the 
discharge of a Leyden jar, was made in 1842 by Prof. 
Joseph Henry* of America. This discovery refers to 

peculiarities concerning the nature of the disruptive dis- 
charge of such a jar; and, it is along the line of these 

peculiarities that most of the recent developments of 
this instrument were made. 

You are probably aware of the fact that when an in- 
sulated body, electrified by friction, is connected to the 

*Prof. Henry clearly recognized the oscillatory char- 
acter of the discharge of a Leyden jar, as will be seen 
from the following quotation from page 377 of the 
44 Proceedings of the American Association for the 
Advancement of Science," for 1850, from a paper 
entitled an " Analysis of the Dynamic Phenomena of 
the Leyden Jar," by Prof. Joseph Henry : 

"Prof. Joseph Henry gave an account of his investigations of 

thti discharge of a Leyden jar. This was a part of a scries of 

experiments he had made a few years ago, on the general subject 

of the dynamic phenomena of ordinary or frictional electricity. 

< >n this subject he had made several thousand experiments. He 

1 ever published these in full, but had given brief notices of some 

of them in the proceedings of the American Philosophical Society. 

All the complex phenomena he had observed could be referred to 

a series of oscillations in the discharge of the jar. If we adopt 

- of a single fluid, then we Bhall be obliged to admit 

'he equilibrium of the fluid, after a discharge takes place, 

-<-ries of oscillations, gradually diminishes in intensity and 

.itude. He had been enabled to show effects from five of 

-inn. The means used f<>r determining 

• mce of these waves was thai of the magnetization of 

Introduced into tin- axic piral. A needle <>f 

thU kind, it Is well known, Is susceptible ol :■ a definite 



62 ELECTRICITY, 

earth by means of a conductor, it is quietly discharged 
by what is technically known as a conductive dis- 
charge. 

If a knuckle of the hand be approached to such a 
body the discharge occurs by means of a spark which 
leaps through the air space, separating the charged 
body from the hand, and, when the discharge is power- 
ful, is attended by a crackling sound or a loud report. 
Such a discharge is called a disruptive discharge. 

If a sharp point or a pin be connected to the conduc- 

amount of magnetism, which is called its saturation. Now, if the 
needle be of such a size as to be magnetized to saturation by 
the principal discharge, it will come out of the spiral magnetized 
to a less degree than that of saturation, by the amount of the 
adverse influence of the oscillations in the opposite direction to 
that of the principal discharge. If the quantity of electricity 
be increased, the power of the second wave may be so exalted 
that the needle will exhibit no magnetrsm ; the whole effect of 
the first or principal wave will be neutralized by the action of 
the second. If the quantity of electricity be greater than this, 
then the needle will be magnetized in an opposite direction. If 
the electricity be still more increased, the needle will again ex- 
hibit a change in its polarity, and so on in succession as the 
power of the successive waves is increased." 

"These experiments had been made several years ago, but 
Prof. H. had not given them in detail to the public, because he 
had wished to render them more perfect. For the last three and 
a half years, all his time and all his thoughts have been given to 
the details of the business of the Smithsonian Institution. He 
had been obliged to withdraw himself entirely from scientific 
research, but he hoped that now the institution had got under- 
way, and the Regents had allowed him some able assistants, that 
he would be allowed, in part, at least, to return to his first love — 
the investigation of the phenomena of nature." 



A HUNDRED YEARS AGO AND TO-DAY, 63 

tor, a stream of electrified air particles is thrown off 
from such point, and will quietly discharge the elec- 
trified body by means of what is called a convective 

discharge. 

Now, in a Leyden jar, the opposite charges on the two 
metallic coatings are held in a bound state by means o[ 
their mutual attractions. When these opposite coatings 
are brought sufficiently near together by means oi a 
conductor a disruptive discharge occurs in the shape o( 
a bright spark attended by a crackling sound. 'This 
discharge is apparently instantaneous, but in 1842 Prof. 
Henry, while studying the peculiar character of the 
magnetization produced by the discharges of Leyden 
jars through magnetizing spirals, came to the conclu- 
sion that such discharges are truly oscillatory in charac- 
that they are not instantaneous, but consist of a 
number of separate discharges and recharges occurring 
in alternately opposite directions. Or, in other words, 
that the disruptive discharge of a Leyden jar partakes 
of the nature of an alternating or rapidly periodic dis- 
charge. 

The character of the magnetization that Henry was 
studying, was what was then called by the Germans 
;ialous magnetization. Henry showed that in reality 
the anomaly was to be traced rather to the peculiar 
nature of the discharge than to that of the magnetiza- 
tion itself. Quoting Henry's own words in a memoir 
published in 1842, he says — 



64 ELECTRICITY 

"The discharge, whatever may be its nature, is not 
correctly represented by a single transfer of the impon- 
derable liquid from one side of the jar to the other; 
the phenomena require us to admit of the existence of 
a principal discharge in one direction and then several 
reflex actions backward and forward each more feeble 
than the preceding, until equilibrium is attained. All 
the facts are shown to be in accordance with this hy- 
pothesis, and a ready explanation is afforded by it of 
a number of phenomena which are to be found in the 
older works of electricity, but which have until this 
time remained unexplained." 

Our ideas ot electrical conduction and propagation 
have been profoundly modified during the past few 
years, largely by reason of difficulties that have arisen 
in the distribution of the electric currents employed for 
feeding incandescent lights that are situated at con- 
siderable distances from the source producing the cur- 
rents. I am, perhaps, justified in the statement that 
there has thus far been found but one successful means 
of so distributing such currents economically when the 
distances exceed certain values. This distribution is ef- 
fected by means of currents, called alternating currents, 
because they rapidly change their direction. 

In systems of alternating current distribution, currents 
of comparatively great differences of potential but of 
small current strength, are sent through a line wire or 
conductor to the points or places at which their energy 



A HUNDRED YEARS AGO AND 10-PAY. 65 

is to be utilized. At such points they are sent through 
devices called transformers, by which they are trans- 
formed both as regards their difference oi potential and 
current strength into currents of comparatively small 
difference of potential but great current strength 

This method oi distribution is more economical than 
could be obtained by the use on such lines of continuous 
currents, from the fact that the size oi die conductors 
can be made very much less for currents o( high poten- 
tial and small current strength, than for those of low 
potential and great current strength. 

Such study, conducted as it was along the lines of 
actual commercial applications, led to many remarka- 
ble discoveries, and I trust you will pardon me if I di- 
gress at this point to ask you to briefly consider a topic 
that is so very often discussed in scientific circles ; viz., 
the relative merits of the so-called pure and the applied 
sciences. For my own part I do not recognize that 
sharp distinction between pure and applied science that 
many of my professional brothers appear to do; but 
far as it does exist, I must confess to a decided belief in 
the value of the applied over that of the so-called pure 
sciences. The only difference that I can really see be- 
tween the two, that can be regarded as of any value, is 
this; that in the case of an applied science the various 
hypotheses or speculations that are formed concerning 
the proper interpretation of the phenomena under dis- 
at once put to the test of extend' 



66 ELECTRICITY, 

mercial use ; and, thus being worked out in cold ma- 
terial, are at once either accepted or rejected ; while it 
is, unfortunately, too often true in the case of a so- 
called pure science, that interpretations of their manner 
of action are obscured by extended explanations of hypo- 
thetical causes, and, not being put to the test of actual 
use, though manifestly improbable, are often kept alive 
by that strange force of authority, which is now happily 
growing of less and less importance in the world of 
science. 

However this may be, there has resulted from this 
practical study of alternating currents, in which the 
highest and best types of both pure and applied science 
have been employed, a knowledge of the peculiarities 
of the flow and other phenomena of such currents that 
has thrown considerable light on the causes of the elec- 
tric force itself. 

Dr. Hertz, Professor in the University at Bonn, has 
made the most marked advance in the direction of a 
theory as to the origin and nature of electric discharges 
by a careful study of the peculiarities of oscillatory 
discharges ; that is, alternating discharges of high fre- 
quency. 

Taking, for example, the disruptive discharge of a 
Leyden jar, Dr. Hertz fixed his attention on the medium 
lying outside of the conductor, through which the dis- 
charge was passing, rather than on the conductor itself. 
By a series of investigations, conducted not only on 



A HUNDRED YEARS AGO AND TO-DAY. 67 

discharges obtained from Leyden jars, but also on those 
obtained from induction coils, the primaries n\ which 
were traversed by alternating currents i)( high fre- 
quency, Hertz has shown, by a singularly complete 
series o\ investigations, that during such discharge, the 
ether lying outside the conductor, is moulded into 
waves that proceed outward in all directions from the 
conductor with the velocity of light lie has shown 
that such waves or vibrations are capable i)( exciting 
sympathetic vibrations in neighboring conductors pro- 
vided, of course, the dimensions of such conductors are 
such as will insure a unison in the rate of vibration 
between the excited and the exciting- waves. Hertz 
names this phenomenon electrical resonance,* and 
shows that it exactly resembles acoustic resonance. 

*The term resonance, as used in physical science, 
referred originally to the case of excited sound waves, 
and related to sympathetic vibrations excited in certain 
bodies, notably, in the air contained within hollow ves- 
sels, such as shells, or jars, or, in the wood of violins, 
guitars, or in the sounding boards of pianos. In all 
- of resonance, the excited waves are of exactly the 
same wave lengths as the exciting waves; or, in other 
words, the pitch or tone cf the two is the same. 

Hertz extended the principle of acoustic resonance to 
the case of the electro-magnetic waves that are pro- 
duced in the space surrounding a conductor through 
which an electric discharge that alternates in its direc- 
tion, such for example as a Leyden jar, is passing. He 
showed that if a circuit be placed near such a conductor 



68 ELECTRICITY, 

Electric radiation being- thus proved to partake of the 
nature of wave motions, all the phenomena characteristic 
of wave motions can be shown to exist in such waves. 
For example, nodes may be formed in conductors 

it will have electric oscillations set up in it, provided its 
dimensions are such that its period of oscillation is 
the same as those in the exciting circuit. 

As in the case of acoustic resonance, so in the anal- 
ogous case of electric resonance, the electrical effects 
produced by the excited waves are similar to those pro- 
duced by the exciting waves. 

In a translation by.Tunzelmann, of a note by Hertz 
in Weidmann's Annalen, published in the London "Elec- 
trician," of Sept. 21st, 1888, on page 626, Hertz says — 

"In order to determine whether, as some minor phenomena 
had led the author to suppose, the oscillations were of the nature 
of a regular .vibration, he availed himself of the principle of 
resonance. According to this principle, an oscillatory current of 
definite period would, other conditions being the same, exert a 
much greater inductive effect upon one of equal period than 
upon one differing even slightly from it." 

"If, then, two circuits are taken having as nearly as possible 
equal vibration periods, the effect of one upon the other will be 
diminished by altering either the capacity of the coefficient of 
self-induction of one of them, as a change in either of them 
would alter the period of vibration of the circuit." 

" This was carried out by means of an arrangement very 
similar to that of Fig. 4. The conductor C C, was replaced by 
a straight copper wire 2.6 metres in length and five millimetres 
in diameter, divided into equal parts as before by a discharger. 
The discharger knobs were attached directly to the secondary 
terminals of the induction coil. Two hollow zinc spheres, 30 
centimetres in diameter, were made to slide on the wire, one 
on each side of the discharger, and since, electrically speaking, 



A HUNDRED YEARS AGO AND [t)-DAY, 69 

through which such discharges arc passing. Waves 
may be so superposed on 011c another, as to produce 

the phenomena ot interference ; that is, electric waves or 
radiations from two sources may he caused to simultane- 

these formed the terminals of the conductor, its Length could be 
varied by altering their position. The micrometer circuit was 
chosen of such dimensions as to have, if the author's hypothesis 
were correct, a slightly shorter vibration period than that of C C. 
It was formed of a square, with sides 7."> centimetres in length, 
of copper wire two millimetres in diameter, and it was placed 
with its nearest side parallel to CB C, and at a distance of 30 
centimetres from it. The sparking distance at the micrometer 
was then found to be 0.9 millimetre. When the terminals of the 
micrometer circuit were placed in contact with two metal spheres 
8 centimetres in diameter, supported on insulating stands, the 
sparking distance could be increased up to 2.5 millimetres. 
When these were replaced by much larger spheres the sparking 
distance was diminished to a small fraction of a millimetre. 
Similar results were obtained on connecting the micrometer 
terminals with the plates of a Kohlrausch condenser. When the 
plates were far apart the increase of capacity increased the 
sparking distance, but when the plates were brought close 
together the sparking distances again fell to a very small value." 

M The simplest method of adjusting the capacity of the micro- 
meter circuit is to suspend to its ends two parallel wires, the 
distance and lengths of which are capable of variation. By this 
means the author succeeded in increasing the sparking distance 
up to three millimetres, after which it diminished when the wires 
were either lengthened or shortened. The decrease of the spark- 
stance on increasing the capacity was naturally to be 
expected ; but it would be difficult to understand, except on the 
principle of resonance, why a decrease of the capacity should 
the same effect." 

u The experiments were then varied by diminishing the capa- 
• lit C B ( shorten ii- period of oscillation, 

and the re irmed those previously obtained, and a B< 



70 ELECTRICITY, 



ously impress their peculiar form of energy on a con- 
ductor so as either to augment or diminish each other's 
intensity of action. Electrical waves may be made to 
suffer reflection, or refraction, or any other phenomena 
of wave motion as manifested by light or by sound 
waves. 

Prof. Lodge* has made some calculations concerning 
the rate of oscillation produced by the discharge of an 
ordinary pint Leyden jar by means of a common dis- 
charging rod as being equal to ten millions per second. 

of experiments in which the lengths and capacities of the circuits 
were varied in different ways, showed conclusively that the maxi- 
mum effect does not depend on the conditions of either one of 
the two circuits, but on the existence of the proper relation 
between them." 

" When the two circuits were brought very close together, and 
the discharger knobs separated by an interval of 7 millimetres, 
sparks were obtained at the micrometer, which were also 7 milli- 
metres in length, when the two circuits had been carefully 
adjusted to have the same period. The induced E.M.F/s must 
in this case have attained nearly as high a value as the inducing 
ones." 

* Prof. Oliver Lodge in his charming work entitled 
" Modern Views of Electricity," says concerning the 
rate of oscillations of an ordinary Leyden jar, on page 
248. London: Macmillan & Co.,. 1889. 

"A common pint Leyden jar discharging through a pair of 
tongs may start a system of ether waves each not longer than 
about 15 or 20 metres ; and its rate of oscillation will be some- 
thing like ten million per second." 

U A tiny thimble-sized jar overflowing its edge may propagate 
waves only about 2 or 3 feet long." 






A HUNDRED TEARS AGO AND TO-DAY. Jl 

Of course I have not been able in the limited time of 
a single lecture to do any more than to give you the 
briefest outline of these very remarkable investigations. 
Hertz's views are almost universally adopted by those 
who have carefully studied the subject. 

Let me now briefly call your attention to some of the 
phenomena concerning what is apparently the simplest 
of all electrical phenomena ; viz., the so-called passage 
or tlow of electricity through a conductor, or, what 
is called electric conduction. 



"The oscillations of currents thus recognized as settiiiLT up 
waves have only a small duration, unless there is some means 
of maintaining them. How long they will last depends partly 
upon the conductivity of the circuit ; but even in a circuit of 
infinite conductivity they must die out if left to themselves, from 
the mere fact that they dissipate their energy by radiation. One 
may get 10 or 100, or perhaps, even 1.000. perceptible oscilla- 
of gradually decreasing amplitude, but the rate of oscil- 
lation is so great that their whole duration may still be an ex- 
tremely small fraction of a second. For instance, to produce 
ether waves a metre in length requires 300,000,000 oscillations 
per second." 

''To keep up continuous radiation naturally requires a supply 
of energy, and unless it is so supplied the radiation rapidly 
ceases. Commercial alternating machines are artificial and cum 
brous contrivances for maintaining electrical vibrations in cir- 
cuits of finite resistance, and in despite of loss by radiation." 

"Inmost commercial circuits the loss by radiation is probably 
.all a fraction of the whole dissipation of energy as to be 

practically negligible ; but one is, of OOUrse, not limited to the 

consideration <»f commercial circuit- or to alternating machines 

as at present invented and u-ed. It may be possible to deyise 

less direci method — some chemical method, perhaps — for 



7 2 ELECTRICITY, 

The flow of electricity through- a wire is an appa- 
rently simple phenomenon. The excited body is placed 
at one end of a conductor, and, almost immediately, it 
produces characteristic phenomena at the other end, 
although hundreds or even thousands of miles distant. 
Up to a very recent date it was believed that electricity 
t passed through the substance of a conductor. Perhaps 
I can best give you the old conception of conduction by 
quoting from the work of Cavallo before referred to. 

"If at the end of the tube opposite to that held in 
the hand a wire of any length be tied, suspending a 
metallic ball at its end, the tube be excited as before 
the metallic ball will, in this case, acquire all the prop- 
supplying energy to an oscillating circuit, and so converting 
what would be a mere discharge or flash into a continuous source 
of radiation." 

" So far we have only considered ordinary practicable elec- 
trical circuits, and have found their waves in all cases pretty 
long, but getting distinctly shorter the smaller we take the cir- 
cuit. Continue the process of reduction in size further, and ask 
what sized circuit will give waves 6000 tenth-metres (three-fifths 
of a micron, or 25 millionths of an inch) long. We have only to 



put 2 7ty} (—.= ) = 0-00006, and we find that the necessary cir< 

cuit must have a self induction in electro-magnetic units, and a 
capacity in electrostatic units, such as their geometric mean is 
10- 5 centimetre (one-tenth of a micron). This gives us at once 
something near atomic dimensions for the circuit, and suggests 
immediately that those short ethereal waves which are able to 
affect the retina, and which we are accustomed to call " light, " 
may be really excited by electrical oscillations or surgings in cir> 
cuits of atomic dimensions," 



A HUNDRED YEARS AGO AND TO-DAY. 73 

erties of the excited tube: i. e., it will attract, sparkle, 
etc., like the tube itself, the electric virtue passing 
through the wire to the ball : hence, the wire is said to 

be a conductor of electricity ; and all such bodies as are 
ible to transmit the electric virtue, like the above- 
mentioned wire, are called conductors." 

"But if, instead of the wire, a silk- string" be used in 
the above experiment, and the tube be excited as be- 
fore, the ball in this case will not show any signs of 
electricity : the silk string- not permitting the electric 
virtue to pass from the tube to the ball : hence the silk 
string in this case, and all those substances through 
which the electric virtues cannot be transmitted, are 
called non-conductors." 

Up to comparatively recent dates practically iden- 
tical views have been held concerning conductors. 
Quite recently, however, our views have changed pro- 
foundly in this respect. According to Hertz, Povnting 
and others, the energy of electric discharges is not 
propagated or transmitted through the conductor itself, 
but through the ether lying outside of the conductor as 
well as that which fills the interatomic and intcrmolec- 
ular spaces within the conductor. This is the medium 
which is known in science as the dielectric and is ordi- 
narily looked on as the non-conductor, or as the insula- 
For example, in the case of a telegraph wire strung 
on insulators and passing through the air between two 
Stations, the air and the glass insulate the said conduc- 



74 ELECTRICITY, 

tor from the earth. According to the modern theory of 
the propagation of electricity, however, the electric 
energy is in reality transmitted through such non-con- 
ducting paths and is rained down on the surface of the 
conductor from the space outside it, the conductor acting 
merely as a sink or place where the electric energy can 
dissipate itself. The electric energy is, therefore, really 
propagated through the so-called non-conductor and 
merely expends its energy, or manifests its characteris- 
tic effects, on the conductor itself. 

Since, as is well known, electric charges are invari- 
ably accompanied by magnetic fields, the electric waves 
or oscillations produced, for example, by the discharge 
of a Leyden jar or induction coil, are generally referred 
to as electro-magnetic waves or oscillations. 

In order to give you a brief description of these 
modern notions I cannot do better than to quote from 
a paper by Prof. Poynting as summarized by Fleming 
on page 476 of Vol. I, of a charming book entitled, 
"The Alternate Current Transformer," which I cannot 
too strongly recommend to you for purposes of study. 

"We see, then, that the energy dissipated in each 
section of the conductor is absorbed into it from the 
dielectric, and the rate of this supply can be calcu- 
lated by Poynting's law for each element of the surface. 
None of the energy of a current travels along the wire, 
but it enters into it from the surrounding non-conductor, 
and as soon as it enters it begins to be transformed into 



A HUNDRED YEARS AGO AND TO-DAY. 

heat, the amount crossing successive layers of the wire 

easing till by the time the centre is reached, where 
there is no magnetic force, it has all been transformed 
into heat. In the original Paper, another simple case 

ted is that of a condenser discharged by a wire. In 
this case, before the discharge, we know that the ei 

les in the dielectric between the plates. If the 
plates are connected by an external wire, according to 
these views the energy is transferred outwards, along the 
electrostatic cquipotential surfaces, and moves on to the 
wire and is there converted into heat. According to this 
hypothesis, we must suppose the lines ot electrostatic 
induction running from plate to plate to move outwards 
as the dielectric strain lessens and whilst still keeping 
their ends on the plates to finally converge in on 
the wire and to be there broken up and their energy 
dissipated as heat. At the same time the wire acquires 
transient magnetic qualities. This means that some 
part of the energy of the expanding lines of electrostatic 
induction is converted into magnetic energy. The 
magnetic energy is contained in ring-shaped tubes of 

netic force which expand outward from between 
the plates and then contract in upon some other part 
of the circuit." 

* 4 The whole history of the discharge may be divided 
into three parts. First, a time when the energy asso- 
ciated with the system is nearly all ele nd is 
sented by the energy of the lines or tubes of elec- 



76 ELECTRICITY, 

trostatic induction running from plate to plate ; second, 
a period when the discharge is at its maximum, when 
the energy exists partly as energy associated with lines 
of electrostatic induction expanding outwards, and 
partly in the form of closed rings or tubes of magnetic 
force expanding and then contracting back on the wire ; 
and then, lastly, a period when nearly all the energy 
has been absorbed or buried in the wire, and has there 
been dissipated in the form of heat, which is radiated 
out again as energy of dark or luminous radiation. The 
function of the discharging wire is to localise the place 
of dissipation, and also to localise the place where the 
magnetic field shall be most intense ; and all that obser- 
vation is able to tell us about a conductor which is con- 
veying that which we call an electric current, is that it 
is a place where heat is being generated, and near 
which there is a magnetic field. These conceptions 
lead us to fresh views of very familiar phenomena. 
Suppose we are sending a current of electricity through 
a submarine cable by a battery, say, with zinc to earth, 
and suppose the sheath is everywhere at zero potential, 
then the wire will be everywhere at a higher potential 
than the sheath, and the level surfaces will pass through 
the insulating material to the points where they cut the 
wire. The energy wmich maintains the current and which 
works the needle at the further end, travels through the 
insulating material, the core serving as means to allow 
the energy to get into motion or to be continually pro- 



HI >^ 



- 



pagaied. This 
transformed 

e adopt the of lig: 

mov. ado still as :t in 

a different form . ,d intermit- 

in the 

- in upo: 
_:it from - -roundi: re to 

be convened into a form in which ~;ain, 

and through which the same in kind is able to affect 
our sen- 

-lam 
alternat: 

the c :h moves in on med 

again, wi:h no othe .ortened 

and the carbo:. :he same 

kind of cha -:: nag 

performed w bit of p 

incande^ in a focus of dark heat. A current through 

a seat o: : - . .:e of di- 

vergence of energy from the condu. 
medium, and this en :id is conw 

and transformed by the rest of From 

aspect the function of the copper cond ire fades 

into insignificance in ii :i comparison 

function of the die of the ether con- 

tained in the die - . . :nc tram- 

>r motor, or lamp worked from a distant dynamo, 
these notions invite us to consider the whole of that 



78 ELECTRICITY 

energy, even if it be thousands of horse-power per hour, 
as conveyed through the ether or magnetic medium, and 
the conductor as a kind of exhaust valve, which permits 
energy to be continually supplied to the dielectric." 

" Consider, for instance, the simple case of an alter- 
nating current-dynamo connected to an incandescent 
lamp by conducting leads. We have in this case a 
closed conducting loop, consisting partly of the arma- 
ture wire, partly of the leads, and lastly of the lamp fila- 
ment. The action of the dynamo when at work con- 
sists in alternately inserting into and withdrawing a 
bundle of lines of magnetic induction from a portion of 
this enclosed area or loop. The insertion of these lines 
of force causes an electro-magnetic disturbance w r hich 
travels away through the enclosed dielectric in the form 
of some strain or displacement in its most generalised 
sense. In reaching the surface of the enclosing con- 
ductor this wave begins to soak into it, the electro-mag- 
netic energy at the same time dissipating itself in it in 
the form of heat. By a suitable arrangement of the re- 
sistances and surfaces of various portions of the circuit, 
we are able to localise the principal place of transforma- 
tion, and to control its rate so as to compel this trans- 
formation of energy to take place at a certain rate in a 
limited portion of the conductor. Energy is then sent 
out thence again in a radiant form, partly in the form of 
ether waves capable of exciting the retina of the eye, 
but very largely in the form of dark heat. The ether, 



A HUNDRED YEARS AGO AND TO-DAY. 79 

or electro-magnetic medium, is, therefore, the vehicle 
by which the energy is earned to the lamp, and con- 
veyed away from it in an altered form, and whatever be 
the translating device employed, the ether is the seat of 
the hidden operations, which are really the fundamental 
ones, and the visible apparatus only the contrivances 
by which the nature of the energy transformation is 
determined and its place defined." 

Passing by a number of highly important discoveries, 
such for example, as that of electrostatic induction and 
the action of dielectrics, I will call your attention for a 
moment to the immortal discovery by Franklin,* in 

* Franklin gives the following description of his kite 
in a letter dated October 19th, 1752, which was pub- 
lished on page in, of a book entitled "Experiments 
and Observations on Electricity, made at Philadelphia 
in America," by Benj. Franklin, L. L. D. and F. R. S. — 

Letter XI. from Benj, Franklin Esq ; of Philadelphia. 

Oct. 19, 1752. 

*• ks frequent mention is made in public papers from Europe 
of the success of the Philadelphia experiment for drawing the 
electric fire from clouds by means of pointed rods of iron erected 
on high buildings, <£t., it may be agreeable to the curious to be in- 
formed that the same experiment has succeeded in PJiilailelphia, 
though made in a different and more easy manner, which is as 
follows : 

%i Make a small cross of two light strips of cedar, the arms so 
long as to reach to tin- four corners of a large, thin silk handker- 
chief when extended ; tie the corners of the handkerchief to the 
extremities of the cro-s. so you have the body of a kite ; which 
being properly accomodated with a tail, loop, and string, will 



80 ELECTRICITY, 

which, by means of the historic kite, raised in Phila- 
delphia in 1742, he established the identity between light- 
ning and electric discharges, and also of the extremely 
practical application he made of such discovery in the 
invention of the lightning rod 



rise in the air, like those made of paper ; but this being of silk, is 
fitter to bear the wet and wind of a thunder-gust without tearing. 
To the top of the upright stick of the cross is to be fixed a very- 
sharp pointed wire, rising a foot or more above the wood. To 
the end of the twine, next the hand, is to be tied a silk ribbon, 
and where the silk and twine join, a key may be fastened. This 
kite is to be raised when a thunder-gust appears to be coming on, 
and the person who holds the string must stand within a door or 
window, or under some cover, so that the silk ribbon may not be 
wet ; and care must bo taken that the twine does not touch the 
frame of the door or window. As soon as any of the thunder clouds 
come over the kite, the pointed wire will draw the electric fire 
from them, and the kite, with all the twine, will be electrified, 
and the loose filaments of the twine will stand out in every way, 
and be attracted by an approaching finger. And when the rain 
has wet the kite and twine, so that it can conduct the electric fire 
freely, you will find it stream out plentifully from the key on the 
approach of your knuckle. At this key the phial may be charged ; 
and from electric fire thus obtained, spirits may be kindled, 
and all the other electric experiments be performed, which are 
usually done by the help of a rubbed glass globe or tube, and 
thereby the sameness of the electric matter with that of lightning 
completely demonstrated." 

B. F. 

As may be readily imagined Franklin's experiment 
created great excitement in scientific circles, and his ex- 
periment in drawing electricity from the air was re- 
peated in different parts of the world. 

The following description of the experiment of De 






A HUNDRED YEARS AGO AND TO-DAY. Si 

Franklin gave directions concerning the proper con- 
struction of lightning rods, that were remarkably com- 
plete considering the state of electrical science at his 
time ; indeed, it has not been until a comparatively re- 
cent date that any question has been called as to the 
correctness oi these directions. 

Franklin's directions were substantially as follows — 
to place somewhere on the outside of the house or 

Romas in this direction is thus described on page 411, 
et al. of Vol. I, of Priestley's work on electricity before 
referred to, — 

" THE greatest quantity of electricity that was ever brought 
from the clouds, by any apparatus prepared for that purpose, 
was by Mr. De Romas, assessor to the presideal of Nerac. This 
gentleman was the first who made use of a wire interwoven in 
the hempen cord of an electrical kite, which he made seven feet 
and a half high, and three feet wide, so as to have eighteen square 
feet of surface. This cord was found to conduct the electricity 
of the clouds more powerfully than a hempen cord would do, even 
though it was wetted ; and, being terminated by a cord of dry 
silk it enabled the observer (by a proper management of his 
apparatus) to make whatever experiments he thought proper, 
without danger to himself." 

" BY the help of this kite, on the 7th of June 17.~>:'>. about one in 
the afternoon, when it was raised, 550 feet from the ground and 
had taken 780 feet of string, making an angle of near forty five de- 
grees with the horizon ; he drew sparks from his conductor three 
inches long and a quarter of an inch thick, the snapping of which 
was heard about 200 paces. Whilst he was taking these sparks, 
he felt, as it were, a cobweb on his face, though he was above 
three feet from the string of the kite; after which he did not 
think it safe to stand so near, and called aloud to all the company 
to retire, as did himself about two feet.'' 



82 ELECTRICITY, 

building to be protected a conductor of such material 
and area of cross section as would permit it to safely 
convey to the earth the heaviest bolt that is apt to fall 

"THINKING himself now secure enough, and not being incom- 
moded by any body very near him, he took notice of what passed 
among the clouds which were immediately over the kite ; but 
could perceive no lightning either there or any where else, nor 
scarce the least noise of thunder, and there was no rain at all. 
The wind was West, and pretty strong, which raised the kite 100 
feet higher, at least, than in the other experiments." 

"AFTERWARDS, casting his eyes on the tin tube, which was 
fastened to the string of the kite, and about three feet from the 
ground, he saw three straws, one of which was about one foot long, a 
second four or five inches, and the third three or four inches, all 
standing erect, and performing a circular dance, like puppets, 
under the tin tube, without touching one another." 

"THIS little spectacle, which much delighted several of the 
company, lasted about a quarter of an hour; after which, some 
drops of rain falling, he again perceived the sensation of the cob- 
web on his face, and at the same time heard a continual rustling 
noise, like that of a small forge bellows. This was a farther 
warning of the increase of electricity ; and from the first instant 
that Mr. De Romas perceived the dancing straws, he thought it 
not adviseable to take any more sparks even with all his precau- 
tions ; and he again intreated the company to spread themselves 
to a still greater distance." 

"IMMEDIATELY after this came on the last act of the enter- 
tainment, which Mr. De Romas acknowledged made him tremble. 
The longest straw was attracted by the tin tube, upon which fol- 
lowed three explosions, the noise of which greatly resembled that 
of thunder. Some of the company compared it to the explosion 
of rockets, and others to the violent crashing of large earthern 
jars against a pavement. It is certain that it was heard into the 
heart of the city, notwithstanding the various noises there." 

" THE fire that was seen at the instant of the explosion had 
the shape of a spindle eight inches long and five lines in diam- 



A HUNDRED TEARS AGO AND TO-DAY. 83 

in that particular latitude. This conductor is to termi- 
nate at its upper end in one or more ooints, and to 
pass at its lower end into permanently moist earth. 
Concerning the advanced ideas as to the protection 
of buildings from lightning in 1795, I will quol 

eter. But the most astonishing and diverting circumstance was 
produced by the straw, which had occasioned the explosion, fol- 
lowing the string of the kite. Some of the company saw it at 
forty rive or fifty fathoms distance, attracted and repelled alter 
nately. with this remarkable circumstance, that every time it was 
attracted by the string, flashes of the tire were seen, and cracks 
-were heard, though not so loud as at the time of the former ex- 
plosion." 

" IT is remarkable, that, from the time of the explosion to the 
end of the experiments, no lightning at all was Been, nor scarce 
any thunder heard. A smell of sulphur wa> perceived, much like 
that of the luminous electric effluvia issuing out of the end of an 
electrified bar of metal Round the string appeared aluminous 
cylinder of light, three or four inches in diameter; and this being 
in the day-time Mr. De Romas did not question but that, if it 
been in the night, that electric atmosphere would have ap- 
peared to be four or five feet in diameter. Lastly, after the ex 
periments were over, a hole was discovered in the ground, per- 
pendicularly under the tin tube, an inch deep, and half an inch 
wide, which was probably made by the large flashes that accom- 
panied the explosions." 

'AN end was put to these remarkable experiments by the 
falling of the kite, the wind being shifted into the East, and rain 
mixed with hail coming on in great plenty. Whilst the kite was 
falling .me foul of a penthouse; and it was no BOOnei 

1. than the person who held it felt such a stroke in his 
hands, and such a commotion through his whole body, afl obliged 
him instantly * string, falling on the f< 

"ther pe re them a shock also, though much more 



84 ELECTRICITY, 

the work of Cavallo before referred to. Speaking of 
the conditions necessary for the proper operation of 
rods Cavallo says : 

" i. That the rod be of such substances as are, in 
their nature, the best conductors of electricity." 

Prof. Richman of St. Petersburgh was not as fortu- 
nate in avoiding the dangers of thus playing with the 
thunder-bolts of Jove. While conducting similar ex- 
periments he received a fatal discharge. Priestley gives 
the following description of this sad accident on page 
416, of the before-mentioned book; viz.: 

" BUT the greatest sufferer by experiments with lightning 
since mankind have introduced so dangerous a subject of their 
inquiries, was professor Richman of Petersburgh before men- 
tioned. He was struck dead, on the 6th of August 1753, by a 
flash of lightning drawn by his apparatus into his own room, as 
he was attending to an experiment he was making with it. There 
were two accounts of this fatal accident communicated to the 
Royal Society, one by Dr. Watson who had it from the best 
authority ; and the other translated from the High Dutch. From 
both these the following is extracted." 

"THE professor had provided himself with an instrument 
which he called an electrical gnomon, the use of which was to 
measure the strength of electricity. It consisted of a rod of 
metal terminating in a small glass vessel, into which (for what 
reason I do not know) he put some brass filings. At the top of 
this rod, a thread was fastened, which hung down by the side of 
the rod when it was not electrified ; but when it was, it avoided 
the rod, and stood at a distance from it, making an angle at th3 
place where it was fastened. To measure this angle, he had the 
arch of a quadrant fastened to the bottom of the iron rod." 

" HE was observing the effect of the electricity of the clouds, 
at the approach of a thunder storm, upon this gnomon ; and, of 
course, standing with his head inclined towards it, accompanied 






A HUNDRED YEARS AGO AND TO-DAY. 85 

2. "That the rods be uninterrupted, and perfectly 
continuous. " 

3. "That they be of sufficient thickness ." 

4. ''That they be perfectly connected with the com- 
mon s/ock." 

5. "That the upper extremity of the rods be as 
accurately pointed as possible. " 

6. "That it is very finch' tapered." 

7. "That it be prominent" 



by Mr. Solokow (an engraver, whom he frequently took with him, 
to be a joint observer of his electrical experiments, in order to 
represent them the better in cuts) when this gentleman, who was 
standing close to his elbow, observed a globe of blue fire, as he 
called it. as big as his fist, jump from the rod of the gnomon 
towards the head of the professor, which was, at that instant, 
at about a foot distance from the rod. This flash killed Mr. 
Richman, but Mr. Solokow could give no account of the particu- 
lar manner in which he was immediately affected by it ; for, at 
the same time that the professor was struck, there arose a sort of 
steam, or vapour, which intirely benumbed him, and made him 
sink down upon the ground ; so that he could not remember even 
to have heard the clap of thunder, which was very loud." 

•THE globe of tire was attended with a report as loud as that 
of a pistol: a wire, which brought the electricity to his metal 
rod. was broken to piece--, and its fragments thrown upon Mr. 
S61ok< Half of the glass vessel in which the rod of 

the gnomon stood was broken off, and the filings of metal that 
were in it were thown about the room." 

•T I'< >N examining the effects of the lightning in the professor*- 

chamber, they found the dooi case hall split through, and the 

dooi torn off. and thrown into the room. They opened a vein 

of the breathless body twice, but no blood followed, and endeav- 

•1 by violent chafing, but in vain. Upon 



86 ELECTRICITY, 

8. "That each rod be carried, in the shortest conve- 
nient direction, from the point at its upper end, to the 
common stock." 

9. "That there is neither large nor prominent bodies 
of metal upon the top of the building- proposed to be 
secured, but such as are connected with the conductor 
by some proper metallic communication." 

10. "That there be a sufficient number of high and 
pointed rods: and" 

11. "That every part of the rod be very substan- 
tially erected." 

turning the corpse with the face downwards, during the rubbing, 
an inconsiderable quantity of blood ran out of the mouth. There 
appeared a red spot on the forehead, from which spirted some 
drops of blood through the pores, without wounding the skin. 
The shoe belonging to the left foot was burst open, and uncover- 
ing the foot at that place, they found a blue mark ; from which 
it was concluded, that the electrical force of the thunder, having 
entered the head, made its way out again at that foot." 

" UPON the body, particularly on the left side, were several red 
and blue spots, resembling leather shrunk by being burnt. 
Many more blue spots were afterwards visible over the who'e 
body, and in particular over the back. That upon the forehead 
changed to a brownish red, but the hair of the head was not 
singed, notwithstanding the spot touched some of it. In the 
place where the shoe was unripped, the stocking was intire ; as 
was the coat everywhere, the waistcoat only being singed on the 
foreflap, where it joined the hinder ; but there appeared on the 
back of Mr. Solokow's coat long narrow streaks, as if red hot 
wires had burned off the nap, and which could not be well ac- 
counted for." 

"WHEN the body was opened the next day, twenty-four hours 
after he was struck, the cranium was very intire, having no 






A HUNDRED TEARS AGO AND TO-DAY, 87 

With, perhaps, the exception of insisting more pro- 
nouncedly on the necessity for grounding the rod, 
modern investigations, up to the time of Lodge's study 
of the lightning rod, had added very little to the re- 
quirements for a good rod. 

As a lightning discharge that passes from the clouds 
to the earth generally takes the shortest path, tall ob- 
jects are the most apt to receive such discharges. Ships 
at sea are, therefore, very liable to be injured by light- 
ning, and until Win. Harris, in 1852, proposed a system 
for the electrical preservation of vessels many good 
ships were destroyed by such discharges. 

Harris' proposition to place lightning rods on ships, 

fissure, nor cross opening ; the brain was found as it possibly 
should be. but the transparent pellicles of windpipe were exces- 
sively tender, gave way, and easily rent. There was some ex- 
travasated blood in it, as Likewise in the cavities below the lungs ; 
those of the breast being quite sound, but those towards the back 
. of a brownish black colour, and tilled witli more of the above 
mentioned blood : otherwise, none of the entrails were touched ; 
but the throat, the glands, and the thin intestines were all in- 
flamed* The Milord leather-coloured spots penetrated the skill 
only. Twice twenty-four hours being elapsed, the body was 30 
far corrupted that it was with diflieulty they got it into a coffin." 

The reasons which led Franklin to suspect the identity 
of the lightning Hash and the electric discharge, arc thus 

iven by him in a letter to Dr. L of Charlestown, 

S. C, dated March 18th, 1755, all( ^ published on pa 

12 of his book entitled ' l Experiments and Observa- 
tions on Electricity made at Philadelphia:" — 

onx question, how I oame iir>t to think of proposing the 



03 ELECTRICITY, 

like many propositions made by scientific men for the 
good of mankind, was first received with very great 
disfavor by the public. Prior to Harris' time, some 
little attempt had been made to protect ships from 
lightning. The work, however, was clumsily done. 
The rods were passed along the masts of the vessel, 
often but a single rod on the mainmast, which was 
carefully separated from any mass of metal in the ship 
and passed down into the water from the end of the 
bowsprit. Such a lightning rod, like an incompetent 
physician or lawyer, is worse than useless, indeed, is 
dangerous, and considerable discredit was thrown on 
the protective power of lightning rods for such reason. 

experiment of drawing down the lightning, in order to ascertain 
its sameness with the electric fluid, I cannot answer better than 
by giving you an extract from the minutes I used to keep of the 
experiments I made, with memorandums of such as I purposed 
to make, the reasons for making them, and the observations that 
arose upon them, from which minutes my letters were afterwards 
drawn. By this extract you will see that the thought was not so 
much " an out-of-the-way one," but that it might have occurred 
to any electrician." 

" Nov. 7, 1749. Electrical fluid agrees with lightning in these 
particulars: 1. Giving light. 2. Colour of the light. 3. Crooked 
direction. 4. Swift motion. 5. Being conducted by metals. 
6. Crack or Noise in exploding. 7. Subsisting in water or ice. 
8. Rending bodies it passes through. 9. Destroying animals. 
10. Melting metals. 11. Firing inflammable substances. 12. 
Sulphureous smell. The electric fluid is attracted by points. 
We do not know whether this property is in lightning. But since 
they agree in all the particulars wherein we can already compare 
them, is it not probable they agree likewise in this ? Let the ex- 
periment be made," 



ONE HUNDRED YEARS AGO AND TO-DAY. 89 

Harris suggested the necessity for connecting the light- 
ning rods with the copper sheathing of the ship's bot- 
tom, and with all masses of metal in the ship, especially 
with the metallic covering of the outside of the powder 
magazines. He was regarded as an innovator of the 
most dangerous type ; but when, after considerable op- 
position, his system was tried and proved to be safe, 
his most violent critics turned mental somersaults and 
proclaimed him a public benefactor. Indeed, so highly 
were his services appreciated by the English Govern- 
ment, that in 1S47 he received the honor of knighthood, 
and is now generally known in science as Sir William 
Snow Harris. 

An amusing story is told concerning the conferring 
of this honor. So little did Harris expect it, that when 
he received a public notification of its grant from Earl 
Russell, he believed that it was a hoax ; and, in order 
to ascertain whether this belief was correct or not, he 
took the letter to a gentleman residing at Plymouth and 
asked him, 'Have you not a collection of autographs 
including that of Sir John Russell?" The autograph 
produced, and, after carefully examining it, he said, 
"No, it is no hoax ; the writing in my note is identical 
with that in yours.'** 

* The history of any great invention is almost invari- 
ably a history of repeated struggles and difficulties. 

These difficulties arise from a variety of circumstances. 
Namely, 



90 ELECTRICITY, 

Prof. Oliver Lodge, bearing in mind the oscillatory 
character of a disruptive discharge, has recently applied 
modern ideas concerning such discharges to the case 

(i.) Those of obtaining the exact conditions neces- 
sary in order to make the invention operative. 

(2.) Those arising from the poverty of the inventor 
or discoverer. 

It too frequently happens that the inventor or dis- 
coverer has given his time so uninterruptedly to the 
particular discovery or invention, that he has neglected 
his ordinary business, and has, for the time being, if 
not for all times, impoverished himself. 

(3.) Difficulties arising from the unwillingness of an 
unthinking public to adopt new ideas, together with the 
general opposition that exists to change or reform of 
any character. 

The history of Harris' improvement of lightning rods, 
especially as applied to the protection of ships at sea, 
is no exception to the general rule. The following ac- 
count of the difficulties that he encountered is thus 
charmingly described in a biographical notice of 
Harris by Chas. Tomlinson, F.R.S., on page xv of a 
" Treatise on Frictional Electricity, in Theory and 
Practice," by Sir William Snow Harris, F.R.S. Lon- 
don : Virtue & Co., Ivy Lanes, Paternoster Row, 1867. 

" Few persons are aware of the long continued struggle Harris 
had to undergo to impress upon the public mind the importance 
of adopting his system of lightning conductors for the ships of 
the Royal Navy, and few are aware of the varied means used for 
the purpose. He contributed a number of papers to the Nau- 
tical Magazine illustrative of damage by lightning ; he was 
always on the watch for the slightest scent of a good case ; and 



A HUNDRED YEARS AGO AND TO-DAY, 9 1 

of lightning rods. He distinguishes two kinds of dis- 
charges as taking place between the earth and a charged 

cloud ; namely, 

(i.) A steady strain or current. 

(2.) An impulsive or oscillatory discharge. 

he never gave it up until he had tracked it to the ship's log de- 
posited in Somerset House, or obtained an account from the 
Captain or one of the oflicers of the ship that had been struck. 
He embodied these cases in Utters and pamphlets, which he cir- 
culated among Members of Parliament and various persons in 
authority, including the foreign ambassadors ; and it may bo 
mentioned to the honour of the Emperor of Kussia, that Harris's 
system was adopted in the Russian Navy before it was fully ad- 
mitted into our own. In 1845 the Emperor presented Harris 
with a valuable ring and a superb vase, in acknowledgment of 
the merits of his system. Harris also instituted a series of ex- 
periments on a large scale, in Plymouth Sound, showing that he 
could direct the discharge to any point of the vessel, or to the 
sea, at pleasure ; and he made the points of discharge evident by 
firing gunpowder. These experiments attracted public notice, 
and crowds assembled on the Hoe to witness them. This led to 
a ludicrous circumstance, which Harris related to the editor with 
great glee. One evening an old woman was passing along the 
Hoe, when a man called her attention to summer lightning that 
was flashing in the horizon. " Don't talk to me about summer 
lightning," remonstrated the incredulous dame; "it. is that Dr. 
Harris playing some of his tricks. If lie doesen't take care, he will 
play them once too often." 

" Harris not only interested himself in protecting ships from 
lightning, but he also endeavoured t<> gel his system applied to public 
buildings. He drew up a long list of buildings that had been 
damaged, not nearly so full and complete as his list of ships, but 
still a formidable indictment againsl folly and prejudice. He 
even addressed a memorial to a Church Building Society, point- 
ing out the necessity of protecting every new church that was 



^2 ELECTRIClTt, 

The former discharge occurs when a cloud gradually 
approaches a point on the earth; the second occurs 
when a cloud discharges suddenly to the earth. Lodge 

built. He invited the editor to accompany him to hear the ver- 
bal reply, which was to this effect, that the cost of fitting conduc- 
tors to a church — viz., from £60 to £100 — was a fatal objection; 
for in many cases this additional charge to the estimates would 
most likely turn the scale against the church being built at all." 

"At length all difficulties in the way of his long cherished ob- 
ject were overcome or removed. All the various objections to 
his conductors had been met : persons in authority had declared 
that letting the copper bands into the masts weakened them ; but 
Harris proved experimentally that their powers of resistance to 
flexure were increased. The flagstaff of a ship, placed on the top 
of the mast above the point where the conductors began, had 
been struck by lightning and shivered to pieces. This and similar 
slight accidents, which really proved the efficiency of the system 
at length were so clearly understood, that no further doubt re- 
mained. It was felt that some public recognition was due to the 
man who had made our ships safe from the attack of a destructive 
foe which had formerly deprived the country of the full services of 
its navy, killed or crippled its sailors, and wasted many thousands 
annually of the public money. In 1847 the honor of knighthood 
was conferred on Snow Harris at the express command of her 
Majesty the Queen, in consideration of his " very useful inven- 
tions," to use the words of Earl Russell. So little was this 
honour expected, that when Earl Russell's letter arrived at Ply- 
mouth, Harris thought it was a hoax ; for he, in common with all 
men of genius, has a strong sense of humour (without which, 
indeed, genius seems to be scarcely complete, unless power take 
its place, as in the case of Milton and Dante), and this humour 
was so often let loose upon his friends in good-natured jokes 
(often practical ones), that no wonder if he were sometimes re- 
paid in his own coin. He took the letter to a gentleman in Ply- 
mouth, and said, ' Have you not a collection of autographs, in- 
cluding that of Lord John Russell?' The autograph in question 



A HUNDRED YEARS AGO AND TO-DAY. 93 

asserts that iron forms as good a substance for a light- 
ning rod as copper, and although he agrees with the plan 
generally followed of connecting all masses of metals 
such as tin roofs, cornices, and gutter spouts with the 

was produced. He examined it carefully, and said. ' No, it is no 
hoax: the writing in my note is identical with that in yours.' 
Rut even then he consulted with his friends whether he had not 
better ask leave to decline the honour ; but he was nervously 
anxious not to appear in the slightest degree to oppose himself 
to her Majesty's gracious wish. He accordingly came up to town 
and received the well-merited honour. The editor called on him 
next day to congratulate him, when he gave an amusing descrip- 
tion of his own feelings on finding himself for the first time in a 
court-dress. He expressed himself extremely gratified at the 
gracious manner of the Queen, and the smile of recognition he 
received from the Prince Consort. IndeeJ, the confidence of her 
Majesty and the Prince in the perfect safety of Harris's conductors was 
shown in a request that he would fit up conductors at Bucking- 
ham Palace and at Osborne, and also similarly protect her Ma- 
jesty's yacht. Harris was also employed some years later to 
design a complete system of conductors for the palace at West- 
minster. His written instructions, which are full of interest, 
were ordered by the House of Commons to be printed, and they 
will be found under the head of 'Estimates. A:c Civil Services, 
for the year ending March 31st, 1866.'" 

"There was now no difficulty in the way of admitting Harri-'s 
conductors into the Royal Navy, and the Government, in con- 
sideration of his great - proposed a vote of £5000 to the 
inventor. Sir James Graham, in moving the vote, said that he 
never voted away money with more pleasure.'' 

" In 1850 Sir William was elected an honorary member of t lie 
Naval Club at Plymouth, when a number of eminent officers 
warmly congratulated him on the great service he had rend 
to the Navy. In 1854 h<- was elected an honorary member of the 
Koyal Yacht Squadron at Cowee, by the consent of all the mem- 
in acknowledgment of his public service-. Nothing could 



94 ELECTRICITY, 

rod, yet he asserts that such connections should prefer- 
ably be made by separately grounded conductors rather 
than directly by the rod itself. 

He also discountenances the direct connection of the 
lightning rod with the building that is to be protected, 
and prefers to have such rod detached from the building 

be more congenial to Sir William's tastes, for he was always more 
of a sailor than a landsman. His very walk reminded you of the 
deck of a ship, and the warmth and simplicity of his character, 
of a sailor. It was quite a treat to be with Harris near or on the 
sea. There was not a craft that he was ignorant of, and he was 
never tired of pointing out the merits and defects of the vessels 
around him. He loved to be on the sea, in whatever craft. The 
editor once accompanied him to the Eddystone in the lighthouse 
tender, and on another occasion to Cornwall in a limestone barge. 
He had invented a new form of ship's compass in which he took 
great interest, and was proud to see it in use. Being told that 
a yacht had arrived in the Sound with one of his compasses 
on board, he asked the editor to go with him to inquire how the 
yachtsman liked it. As soon as he got on board and sent in his 
message, the proprietor came up and said, ' Oh ! I don't like 
your compass at all ; but I have one here by a man named Har- 
ris that is a great favourite of mine.' 'I'm Harris,' was the 
bursting, eager reply, whereupon apologies and warm congratu- 
lations ensued." 

" Sir William had long had a yacht of his own, in the manage- 
ment and sailing of which he took the greatest delight. He was 
proud of his nautical skill, and was pleased when some one told 
him that a naval man once observing a sailing-boat tacking 
about the Sound, exclaimed, ' Egad, the fellow in that boat well 
knows what he's about ! ' It need hardly be said that the fellow 
was Harris himself. He had many other characteristics of a sailor, 
but there is one point in which he did not resemble Jack Tar : 
that is, in his indifference to dancing, although, as we have said, 
he was an accomplished musician." 



A HUXPRKD YEARS AGO AND TO-DAY, 95 

by means oi good glass insulators. He also recom- 
mends the use ot a stranded conductor rather than the 
solid conductors generally employed.* 

* There is even yet no little diversity of opinion con- 
cerning; the exact conditions that should be fulfilled in 
order to best ensure lightning; protection. The question 
of lightning- protection came up before the ''Meeting of 
the British Association at Bath in [888, and considerable 
discussion followed. Prof. Lodge, in a sketch of the 
electrical papers read before Section A, of such meeting, 
thus ably and humorously describes the discussion in 
the London " Electrician, n — I quote from a reprint in 
the "Electrical Engineer/' N. Y. , Vol. VII, iSSS, page 

" And now we have cleared the course fur the lightning rod 

discussion, which excited a good deal of interest, and which really 

di>cussion. in which many prominent members of the Beo- 

lion took part, and on which much more might have been said 

had there been time." 

*• The di>cussion is being reported in this journal pretty nearly 

verbatim; but out of such a mass of matter it would be diffi- 
cult for any one to pick out the salient points of difference be- 
tween the opposite camps, and it may be useful to bring them 
into more marked relief.'' 

M The opposite camps may be styled the Practical vs. the 
Theoretical. On the one side we find constructors of lightning 
members of the lightning rod conference, meteorologists, 
and engineers ; a miscellaneous body of great experience headed 
for the time being with efficiency and good humor by the presi- 
dent of Section G, who lias necessarily in his official position an 
enormous number of lightning protectors under his super- 
on." 

u On the other side we find some laboratory experiments, and a 
theory of the alternating character of a discharge, combined with 



96 ELECTRICITY, 

a mania for talking about self-induction or electro-magnetic 
inertia, and for poking this idea into a lot of places where it does 
not naturally seem to fit ; excluding its influence, however, from 
other places where one would expect to find it, such as the in- 
terior of an iron rod." 

" If views and statements so founded are to make headway 
against the experience of practical men, and to gradually intro- 
duce reform into existing procedure, it must be by reiterated 
statement and discussion, and after gradually acquired further 
experience under circumstances and conditions arranged to test 
the new views on a large scale. On the other hand, if the self- 
induction mania has no sound basis in fact, the surest way of de- 
stroying it is to bring it into the arena and expose it to conflict. 
Hence it is that the organizing committee of Section A arranged 
for the opposite camps to meet and skirmish at Bath." 

" The combat was not waged to the death, the lists being 
cleared before the combatants were half exhausted, so that it is 
quite possible that they may meet again on some other arena. 
Meanwhile, the points at issue may be summarized thus: selecting 
those statements of Mr. Preece and his supporters which seem 
most generally accepted, or likely to be accepted, on that side ; 
and numbering the opposing statements so as to correspond 
with them. No statement is here quoted or suggested which, to 
the writer, seems entirely absurd ; because absurd statements 
may easily be made in debate without sufficient thought, and be- 
cause such statements are not likely to be generally or weightily 
accepted, even if pressed by their propounder." 

Statements made in the Practi- Statements made in the Theoret- 
cal Camp ical Camp, 

1. Properly constructed 1. Rods as at present con- 

lightning rods never fail. When s t r u c ted, though frequently 
existing rods fail it is because successful, may and do some- 
there is something the matter times fail, even though their 
with them — usually an insuifi- earth is thoroughly good ; the- 
cient earth. reason being that they offer to 

a flash a much greater obstruc- 
tion — a much worse path — 



A HUNDRED YEARS AGO AND IO-DAY. 






2. Ley den jar discharges 
have nothing oscillatory or al- 
ternating about them, or at 
least the existence of such al- 
ternations is an unproved as- 
sumption. 



3. Even if Leyden jar dis- 
charges should turn out to be 
oscillatory, there is no re 
why lightning flashes should be 
of the same character. L :'_ 
ning flashes have an apparent 
duration, and transmit tele- 
graph signals, deflect c<>m 
and do other thi 
which alternating curre: 
could not do. 



than is usually BUppoeed : an 

obstruction to be reckoned in 
hundreds or thousands of ohms, 
even for a very thick copper 
wire. 

2 When a Leyden jar ia 
charged it corresponds to a bent 
Bpring, and its discharge cor- 
responds to the release of the 
spring. Its discharge current 
alternates, therefore, in the 
same way and for much the 
same reason as a twitched reed 
or tuning fork vibrates. The 
vibrations decay in either case 
because of frictional heat pro- 
duction, and because of the 
emission of waves into the sur- 
rounding medium. A s 
spark of a Leyden jar, exam- 
ined in an exceedingly fast re- 
volving mirror, is visibly drawn 
out into a close succession of 
oppositely-directed disehar. 
although its whole duration is 
so excessively minute. 

3. A lightning flash is a 
spar D cl<»ud and earth, 

which are two oppositely elec- 
trified flat surfaces, and 
flash cor therefor* 

internal sparking between 
the two plates of a great air 
condenser. All the conditions 
which apply to ■ i- l< D jar 

liabi- rne for light n. 



93 



ELECTRICITY, 



4. The one thing needful for 
an efficient lightning protec- 
tor is conductivity, sufficient 
conducting power to convey 
the whole charge quickly and 
harmlessly down to the earth, 
with which the conductor must 
make elaborate contact. 



Sometimes the resistance met 
with, either in the cloud itself 
or in the discharger, may be so 
great that the epark ceases to 
be oscillatory, and degenerates 
into a fizz or rapid leak ; but 
there can be no guarantee that 
it shall always take this easily 
manageable form ; and it is 
necessary in erecting protectors 
to be prepared for the worst 
and most dangerous form of 
sudden discharge. The appar- 
ent duration of a lightning 
flash is due to its frequently 
multiple character, and indi- 
cates successive discharges, not 
one long-drawn out one. Noth- 
ing that lightning has been 
found to do disproves its oscil- 
latory character ; because Ley- 
den jar discharges, which are 
certainly oscillatory, can do 
precisely the same. 

4. Although some conductiv- 
ity is necessary for a lightning 
conductor, its amount is of far 
less consequence than might be 
expected. The obstruction met 
with by an alternating or rap- 
idly varying discharge depends 
much more on electromagnetic 
inertia or self induction than 
upon common resistance. So 
much obstruction is due to this 
inertia that a trifle more or less 
of frictional resistance in ad- 
dition, matters practically not 









A HINDKED YEARS AGO AND TO-DAY. 



99 



5. No danger is to be feared 
from a lightning conductor if 
only it will be well earthed and 
be sufficiently massive not to be 
melted b y a discharge. All 
masses of metal should be con- 
nected to it, that they may be 
electrically drained to earth. 



at all. It is very desirable to 
have a l:(»(h! and deep earth in 

order to protect foundations 
and gas and water mains from 
damage, and in order to keep 
total impedance as low as pos- 
sible. 

5. The obstruction offered by 
a lightning rod to a discharge 
being so great, and the current 
passing through it at the in- 
stant of the flash being enor- 
mous, a very high difference of 
potential exists between every 
point of the conductor and the 
earth, however well the two are 
connected; hence the neighbor- 
hood of a lightning conductor 
is always dangerous during a 
storm, and great circumspec- 
tion must be exercised as to 
what metallic conductors are 
wittingly or unwittingly 
brought near or into contact 
with it. AVhen a building is 
struck the oscillations and sur- 
gings all through its neighbor- 
hood are so violent that every 
piece of metal is liable to give 
off sparks, and gas may be 
lighted even in neighboring 
houses. If one end of a rain- 
water gutter is attached to a 
struck lightning conductor the 
other end is almost certain to 
spit off a long spark, unless it 
is also metallically connected. 
Electric charg* >a -plash about 



IOO 



ELECTRICITY, 



6. The shape of the sectional 
area of a conductor is quite 
immaterial; its carrying power 
has nothing to do with extent 
of surface; nothing matters in 
the rod itself but sectional area 
or weight per foot run, and con- 
ductivity. 



7. Points, if sharp, should 



in a struck mass of metal, as 
does the sea during an earth- 
quake or when a mountain top 
drops into it. Even a small 
spark near combustible sub- 
stances is to be dreaded. 

6. The electrical disturbance 
is conveyed to a conductor 
through the ether or space sur- 
rounding it, and so the more 
surface it exposes the better. 
Better than a single rod or tape 
is a number of separate lengths 
of wire, each thick enough not 
to be easily melted, and well 
separated so as not to interfere 
with each other by mutual in- 
duction. 

The liability of rods to be 
melted by a flash can be easily 
over-estimated . A rod usually 
fails by reason of its inertia- 
like obstruction, and conse- 
quent inability to carry off the 
discharge without spittings and 
side flashes ; it very seldom 
fails by reason of being melted. 
In cases where a thin wire has 
got melted, the energy has been 
largely dissipated in the effort, 
and it has acted as an efficient 
protector ; though, of course, 
for that time only. Large sec- 
tional area offers very little ad- 
vantage over moderately small 
sectional area, such as No. 5 
B. W. G. 

7 Points, if numerous 



ONE HUNDRED YEARS AGO AND TO-DAY. 



IOI 



constitute so great a protec- 
tion that violent flashes to 
them ought never to occur. 



8. Lightning conductors, if 
frequently tested for continui- 
ty and low resistance by ordi- 
nary galvanic currents, are 
bound to carry off any dis- 
charge likely to strike them, 
and are absolutely to be de- 
fended upon . The easiest path 
pr< »t eet s all ot her possible paths. 



enough, serve a very useful 
purpose in neutralizing the 
charge of a thunder-cloud hov- 
ering over them, and thus often 
prevent a Hash; but there are 
occasions, easily imitated in 
the laboratory, when they are 
of no avail; for instance, when 
one upper cloud sparks into a 
lower one, which then suddenly 
overflows to the earth. In the 
case of these sudden rushes, 
there is no time for a path to 
be prepared by induction, no 
time for points to exert any 
protective influence, and points 
then get struck by a violent 
flash just as if they were knobs. 
Discharges of this kind are the 
only ones likely to occur dur- 
ing a violent shower; beciuse 
all leisurely effects would be 
neutralized by the raindrops 
better than an infinitude of 
points. 

8. The path chosen by a gal- 
vanic current is no secure indi- 
cation of the course which will 
be taken by a lightning flash. 
The course of a trickle down a 
hillside does not determine the 
path of an avalanche. Lightning 
will not select the easiest path 
alone; it can distribute itself 
among any number of possible 
paths, and can make paths for 
it -'-if. Ordinary testing of con- 
ductor-, therefore, is no guaran- 



102 



ELECTRICITY, 



9. A certain space contigu- 
ous to a lightning rod is com- 
pletely protected by it, so that 
if the rod be raised high enough 
a building in this protected 
region is perfectly safe. 



tee of safety, and may be mis- 
leading. At the same time it 
is quite right to have some 
system of testing and of inspec- 
tion, else rust and building 
alterations may render any 
protector useless. 

9. There is no space near a 
rod which can be definitely 
styled an area of protection, 
for it is possible to receive vio- 
lent sparks or shocks from the 
conductor itself. Not to speak 
of the innumerable secondary 
discharges which, by reason of 
electro-kinetic momentum and 
of induction and of the curi- 
ous recently discovered ef- 
fect of the ultra-violet light of 
a spark, are liable to occur as 
secondary effects in the wake 
of the main flash. 



"Just one word on the subject of iron vs. copper. The writer 
last year thought and stated that, in so far as the substance of 
the conductor was magnetized by the discharge, iron would ob- 
struct a lightning flash or any other rapidly varying current 
enormously more than copper does. But the fact is, that the 
substance of a conductor is, by sufficiently rapidly alternating 
currents, not magnetized at all. The current is tubular, keeps 
wholly to the outer surface, and magnetizes nothing inside. 
Hence the magnetizability of the substance of a conductor is of 
no moment at all ; and iron, therefore, will do every bit as well as 
copper. Mr. Preece's experience with half a million iron wire 
telegraph post protectors leads him to uphold iron as entirely 
satisfactory. So, on this one point, as well as on the necessity 
existing for a good earth, a portion of the practical and theoreti- 
cal camps have been able to agree." 



A HUNDRED YEARS AGO AND TO-DAY. IO3 

A memorable discovery was made in 1786, by Luigi 
Galvani,* professor of Anatomy in the University of 



* It is a curious fact that much difference of opinion 
existed in scientific literature of the time of Galvani 
concerning the light in which he himself viewed his 
►very. That Galvani knew the effects which elec- 
tricity produced in animal organisms there can be no 
doubt, for he had long before experimented with the 
effects of electrical discharges on such organisms. 
When he saw the convulsive movements of the frog's 
- produced, as he thought entirely without the inter- 
vention of any electrical discharge, he imagined that he 
had discovered, not a new electric source outside the 
's legs, but either a true vital fluid, or, as he after- 
wards appeared to believe, an electric source within the 
frog ; i. e. , that the frog preparation was itself an electric 
source, and this, as we know, is true. The great dis- 
covery that the combination of metals outside the frog 
formed a true electric source, was afterwards made by 
Volta and not by Galvani. 

In a "Supplement to the Encyclopaedia, or Dictionary 

of Arts, Sciences, and Miscellaneous Literature," pub- 
lished in Philadelphia in 1803, the following description 

iven under the head "Galvanism" on page 73, ofi 
Vol. II. of the Supplement ; viz., 

"GALVANISM, is the name now commonly given to the infiu- 

>vered nearly eight year- ago by the celebrated Galvani, 

BSSOI of Anatomy at Bologna, and which, by him and some 

other authors, has been called animal electricity. We prefer the 

former name, because we think it is by no means proved, that 

phenomena discovered by Galvani depend either upon the 

-ic fluid, or upon any law of animal life. While thai IS the 



104 ELECTRICITY, 

Bologna. Galvani was engaged in a series of observa- 
tions as to the effects of atmospheric electricity on 
animal organisms, and had employed the hind legs of 
recently killed frogs as sensitive electroscopes. He 

case, it is surely better to distinguish a new branch of science by 
the name of the inventor, than to give it an appellation which 
probably may, and, in our opinion, certainly does, lead to an 
erroneous theory." 

"M. Galvani was engaged in a set of experiments, the object of 
which was to demonstrate, if possible, the dependence of muscu- 
lar motion upon electricity. In the course of this investigation, 
he had met with several new and striking appearances which 
were certainly electrical ; soon after which, a fortunate accident 
led to the discovery of the phenomena which constitute the 
chief subject of this article. The strong resemblance which 
these bore to the electrical facts which he had before observed, 
led almost irresistibly to the conclusion that they all depended 
on the same cause. This opinion he immediately adopted ; and 
his subsequent experiments and reasonings were naturally di- 
rected to support it. The splendor of this discovery dazzled the 
imaginations of those who prosecuted the enquiry; and for some 
time his theory, in so far at least as it attributed the whole to 
the agency of the electric fluid, was sanctioned by universal 
approbation. Of late, however, this opinion has rather lost 
ground ; and there are now many philosophers who consider the 
phenomena as totally unconnected with electricity ." 

"We propose, in the first place, to enumerate the chief facts 
which have been ascertained on the subject ; we shall then en- 
quire, whether or not the cause of the appearances be the electric 
fluid ; and, thirdly, we shall examine how far it has been proved, 
that this cause is necessarily connected with animal life." 

" Whilst Galvani was one day employed in dissecting a frog, in 
a room where some of his friends were amusing themselves with 
electrical experiments, one of them having happened to draw a 
spark from the conductor at the same time that the professor 



A HUNDRED YEARS AGO AND TO-DAY. 105 

noticed, that when the nerves of such preparations were 

connected with the muscles of the leg by means oi 
metallic conductors, that the legs were violently con- 
vulsed. 

touched one of the nerves of the animal, its whole body was 
instantly shaken by a violent convulsion. Astonished at the 
phenomenon, and at first imagining that it might be owing to 

his haying wounded the nerve, he pricked it with the point of his 
knife, to assure himself whether or not this was the case, but no 
motion of the frog's body was produced. He now touched the 
nerve with the instrument as at iirst. and directed a spark to be 
taken at the same time from the machine, on which the contrac- 
tions were r?newed Upon a third trial, the animal remained 
motionless : but observing that lie held his knife by the handle, 
which was made of ivory, he changed it for a metallic one, and 
immediately the movements took place, which never was the case 
when he used an electric substance." 

"After having made a great number of similar experiments 
with the electrical machine, he resolved to prosecute the subject 
with atmospheric electricity. With this view he raised a con- 
ductor on the roof of his house from which he brought an iron 
wire into his room. To this he attached metal conductors, con- 
d with the nerves of the animals destined to be the subject 
of his experiments ; and to their legs he fastened wires which 
reached the floor. These experiments were not confined to frogs 
alone. Different animals, both of cold and warm blood, were 
subjected to them : and in all of them considerable movements 
were excited whenever it lightlied. These preceded thunder, and 
corresponded with its intensity and repetition : and even when no 
lightning appeared, the movements took place when any Btormy 
cloud passed over the apparatus. 'I hat all these appearances 
were produced by the electric fluid, was obvions." 

"Having soon after this suspended some frogs from the iron 
palisades which surrounded his garden, by mean- of metallic 
hooks fixed in the spine- of their back-, he observed that their 
muscles contracted frequently and involuntarily as i-f from a 



I06 ELECTRICITY, 

Galvani had long been searching- for the presence of 
a vital force or fluid which could be assigned as the 
cause of vitality ; and, when he saw the movements of 

shock of electricity. Not doubting that the contractions depended 
on the electric fluid, he at first suspected that they were connected 
with changes in the state of the atmosphere. He soon found, 
however, that this was not the case ; and having varied, in many 
different ways, the circumstances in which the frogs were placed, 
he at length discovered that he could produce the movements at 
pleasure by touching the animal with two different metals, 
which, at the same time, touched one another either immediately 
or by the intervention of some other substance capable of con- 
ducting electricity.'' 

"All the experiments that have yet been made may be reduced 
to the following, which will give the otherwise uninformed reader 
a precise notion of the subject.'' 

"Lay bare about an inch of a great nerve, leading to any limb 
or muscle. Let that end of the bared part which is farthest from 
the limb be in close contact with a bit of zinc. Touch the zinc 
with a bit of silver, while another part of the silver touches, 
either the naked nerve, if not dry, or, whether it be dry or not, 
the limb or muscle to which it leads. Violent contractions are 
produced in the limb or muscle, but not in any muscle on the 
other side of the zinc." 

"Or, touch the bared nerve with a piece of zinc, and touch, 
with a piece of silver, either the bared nerve, or the limb ; no 
convulsion is observed, till the zinc and silver are also made to 
touch each other." 

"A fact so new, illustrated by many experiments and much in- 
genious reasoning, which Professor Galvani soon published, 
could not fail to attract the attention of the physiologists all 
over Europe ; and the result of a vast number of experiments, 
equally cruel and surprising, has been from time to time laid 
before the public by Valli, Fowler, Monro, Volta, Humboldt, and 
others." 



A HUNDRED YEARS AGO AND TO-DAY. I07 

the frog's legs he thought he had discovered the true 
vital fluid. Galvani's observations produced an excite- 
ment throughout the scientific world fully equal to that 
produced by the invention of the Leyden jar, and his 
experiments were repeated by acute observers in all 
parts of the scientific world. 

Among- other investigators in this field was Alexander 
Volta. At first he accepted Galvani's explanation as to 
the cause of the phenomena observed in the frog's leg, 
but soon afterwards he came to the conclusion that 
what Galvani had actually discovered was not the 
cause of vitality, but a new method of producing 
electricity. 

Volta conducted an extended series of investigations 
which in 1796 resulted in the invention of the voltaic 
pile.* This invention may generally be regarded as 

* In a letter in French to Sir Joseph Banks read by 

the latter to the Royal Society on the 26th of June, 

1800, Volta thus described, in Transactions of the Royal 

ty for the year 1800, on p. 403, his great discovery of 

the pile and I append a translation of parts of the above. 

A Come en Milanois, ce 20me Mars, 1800. 

"Apres un long silence, dont je ne chercherai pas a m'excuser, 

j'ai le plaisir de voufl oommuniquer, Monsieur, et par votre 

moyen a la Societe Royale, quelques resultats frappants auxquels 

ifl arrive, en poursoivant ines experiences sur Telectricite 

excitee par le simple contact mutuel des mctaux de differente 

espece, et meme par celui des autres conducteurs, aussi differents 

;x, BOit Liquides, BOit contenant quelque humeur, a laquelle 

il- doivent proprement leur pouvoir conducteur. Le principal 



Io8 ELECTRICITY, 

one of the most important ever made in electrical 
science. 

Volta's invention of the electric pile belongs to the 

de ces resultats, et qui comprend a-peu-pres tous les autres, est 
la construction d'un appareil qui ressemble pour les effets, c'est- 
a-dire, pour les commotions qu'il est capable de faire eprouver 
dans les bras, &c. aux bouteilles de Leyde, et mieux encore aux 
batteries electriques foiblement chargees, qui agiroient cependant 
sans cesse, ou dont la charge, apres chaque explosion, se re- 
tabliroit d'elle-meme ; qui jouiroit, en un mot, d'une charge in- 
defectible, d'une action sur le fluide electrique, ou impulsion, 
perpetuelle ;" 

" Je vais vous donner ici une description plus d^taillee de cet 
appareil." 

" Je me fournis de quelques douzaines de petites plaques rondes 
ou disques, de cuivre, de laiton, or mieux d'argent, d'un pouce 
de diametre, plus ou moins, (par exemple, de monnoyes,) et d'un 
nombre egal de plaques d'etain, ou, ce qui est beaucoup mieux, 
de zinc, de la meme figure et grandeur, a-peu-pres ; je dis a-peu- 
pres, parcequ'une precision n'est point requise, et, en general, 
la grandeur, aussi bien que la figure, des pieces metalliques, est 
arbitraire : on doit avoir ejard seulment qu'on puisse les arranger 
commodement les unes sur les autres, en forme de colonne. Je 
prepare en outre, un nombre assez grand de rouelles de carton, 
de peau, ou de quelque autre matiere spongieuse, capable d'im- 
biber et de retenir beaucoup de l'eau, ou de l'humeur dont il fau- 
dra, pour le succes des experiences, qu'elles soient bien trempees. 
Ces tranches ou rouelles, que j'appelerai disques mouilles, je les 
fais un peu plus petites que les disques ou plateaux metalliques, 
afin qu'interposees a ceux, de la maniere que je dirai tantot, ils 
n'en debordent pas." 

"Ayant sous ma main toutes ces pieces, en bon etat, c'est-a- 
dire, les disques metalliques bien propres et sees, et les autres 
non-metalliques bien imbibes d'eau simple, ou, ce qui est beau- 
coup mieux, d'eau salee, et essuyes ensuite legerement, pour que 
l'humeur n'en degoutte pas, je n'ai plus qu'a les arranger comme 
il convient ; et cet arrangement est simple et facile." 



A HUNDRED YEARS AGO AND TO-DAY. IOo 

third class of great ideas or inventions ; namely, that of 
fruitful inventions, because mature and timely. 

:a, however, was so far in advance of his co- 

" Je pose done horizontalement sur une table ou base quelque 
conque, un des plateaux metalliques, par exemple, un d'argent. et 
sur ce premier j'en adapte un second de zinc ; sur ce second je 
couche un des disques mouilles ; puis un autre plateau d'argent, 
suivi immediatement d'un autre de zinc, auquel je fais succeder 
encore un disque niouille. Je continue ainsi, de la meme facon, 
accouplant un plateau d'argent avec un de zinc, et tou jours dans 
le meme sens, c est-a-dire, toujours l'argent dessous et le zinc 
dt ssus. on nice versa, selon que j'ai commence, et interposant k 
chacun de ces couples, un disque mouille ; je continue, dis-je, 
a former, de plusieurs de ces etages, une colonne aussi haute 
qu'elle pent se soutenir sans s'ecrouler.'' 

"After a long 6ilence, for which I do not attempt to excuse 
myself, I have the pleasure, Sir, to communicate to you, and 
through you to the Royal Society, some striking results which I 
have just obtained, in carrying on my experiments on the elec- 
tricity excited by the simple, mutual contact of different kinds 
of metals, and even by that of other conductors, sufficiently dif- 
ferent from one another, either liquids or substances contain- 
ing some moisture, to which strictly speaking they owe their 
conducting powers. The principal of these results, which in- 
cludes nearly all the others, is the construction of an apparatus 
which resembles so far as its effects are concerned, that is by the 
commotion which it is capable of making one feel in the arms, 
<fcc. the Leyden batteries, and still more the fully charged elec- 
tric batteries. It acts, however, without ceasing, and its charge 
tablishea itself after each explosion. It operates, in a word, 
by an indestructible charge, by a perpetual action or impulse on 
the electric fluid." 

" I will here give you a detailed description of this apparatus." 

u l obtain several dozen -mall round plates or discs of copper, 
brass, or better of silver, of an inch in diameter more or less, M for 
example coin.-." and an equal number of plates of tin or what is 
still better of zinc of the same shape and >ize approximately ; I 



IIO ELECTRICITY, 

laborers, that he occupies the peculiar position of hav- 
ing no rivals for this invention ; at least, I believe this 
is the "case. 

say approximately, because precision is not requisite; in general, 
the size as well as the figure of the metal pieces is arbitrary ; we 
should have care only that we can conveniently arrange them 
one over the other in the form of a column. I prepare besides a 
sufficiently great number of discs of card-board, of cloth, or of 
some other spongy material, capable of imbibing and retaining 
considerable water or other liquid; for, it is necessary for the 
success of the experiment that they should be well moistened. 
These sections or discs, which I will call moistened discs, are made 
slightly smaller than the metal discs in order that they may be 
interposed between the other discs without projecting beyond 
them." 

"Having these pieces conveniently arranged, and in good condi- 
tion, that is to say the metal discs clean and dry, and the non-metal- 
lic discs sufficiently moistened with water, or what is still better salt 
water, they are then lightly pressed in order to prevent the liquid 
from running out. I have then only to arrange them as desired 
and this arrangement is simple and easy. 

I place, generally horizontally, on a table or other base one of 
the metallic plates, for example, one of silver; on this first, I then 
place a second of zinc ; on this second, I place a moistened disc ; 
then another plate of silver, followed immediately by another 
of zinc to which I can make succeed a moistened disc. I 
then continue in the same manner coupling a plate of silver 
with one of zinc, and always in the same direction, that is to say 
always the silver above the zinc below, or vice versa, according 
as I have commenced, interposing between each of these discs a 
moistened disc; I continue I say to form by many of these sets a 
column sufficiently high that it may be able to stand upright." 

The communication then goes on to describe the man- 
ner in which electrical effects can be obtained from this 
pile or battery by connecting the end plates to the elec- 
tro-receptive device that is to receive its discharge. 



A HUNDRED YEARS AC.o AND TO-DAY. Ill 

With this new and ready moans for producing elec- 
tricity placed at the disposal of investigators, a host o( 

valuable inventions and discoveries followed. For ex- 
ample, in 1S00, Nicholson and Carlisle* made the im- 



* The following- description is thus given by Nichol- 
son in Vol. IV, of a serial publication entitled, "A 
journal ot Natural Philosophy, Chemistry, and the 
published in London in 1S01, in a paper on an 
'Account of the New Electrical Apparatus of Sig. Alex. 
Volta, and Experiments performed with the Same." On 
page 182 in this article the following description is given 
of the decomposition of water : — 

" In all these experiments it was observed, that the action of 
the instrument was freely transmitted through the usual conduc- 
tors of electricity, but stopped by glass and other non-conductors. 
Wry early in this course, the contacts being made sure by plac- 
ing a drop of water upon the upper plate, Mr. Carlisle observed 
a disengagement of gas round the touching wire. This gas, 
though very minute in quantity, evidently seemed to me to have 
the smell afforded by hydrogen when the wire of communication 
~ T eel. This, with some other facts, led me to propose to 
break the circuit by the substitution of a tube of water between 
two wires. ( )n the 2d of May we, therefore, inserted a brass wire 
through each of two corks inserted in a glass tube of half an inch 
internal diameter. The tube was filled with New river water, and 
the distance between the points of the wires in the water was one 
inch and three-quarters. This compound discharger was applied 
so that the external ends of its wire were in contact with the two 
extreme plates of a pile of thirty-six half crowns with the corre- 
spondent pi< ces of zinc and pasteboard. A fine stream of minute 
bubbles immediately began to How from the point of the lower 
wire in the tube, which communicated with the silver, and the 
opposite point of the upper wire became tarnished, first deep 
ud then black. On reversing the tube, the gas came 



112 ELECTRICITY, 

portant discovery that an electric current passed through 
a compound liquid decomposes the liquid. Employing- a 
voltaic pile consisting of thirty-six English half crowns, 
alternating with as many discs of zinc and paste-board 



from the other point, which was now lowest, while the upper in 
its turn became tarnished and black. Reversing the tube again, 
the phenomena again changed their order. In this state the 
whole was left for two hours and a half. The upper wire gradu- 
ally emitted whitish filmy clouds, which, towards the end of the 
process, became of a pea green colour, and hung in perpendicular 
threads from the extreme half inch of the wire, the water being 
rendered semi-opaque by what fell off, and in a great part lay, of 
a pale green, on the lower surface of the tube, which, in this dis- 
position of the apparatus, was inclined about forty degrees to 
the horizon. The lower wire of three quarters of an inch long, 
constantly emitted gas, except when another circuit, or complete 
wire, was applied to the apparatus ; during which time the emis- 
sion of gas was suspended. When this last mentioned wire was 
removed, the gas re-appeared as before, not instantly, but after 
the lapse of four beats of a half second clock standing in the 
room. The product of gas, during the whole two hours and a 
half, was two-thirtieths of a cubic inch. It was then mixed with 
an equal quantity of common air, and exploded by the applica- 
tion of a lighted waxed thread." 

" It might seem almost unnecessary to have reversed the order 
of the pile in building up, as reversing the tube must have 
answered exactly the same purpose. We chose, however, to do 
this, and found that when the zinc was at the bottom, its effects 
were reversed, that is to say, the gas still came from the wire 
commnicating with the silver, &c . " 

" We had been led by our reasoning on the first appearance of 
hydrogen to expect a decomposition of the water ; but it was 
with no little surprise we found the hydrogen extricated at the 
contact with one wire, while the oxigen fixed itself in combina- 
tion with the other wire at the distance of almost two inches. 



A HUNDRED YEARS AGO AND TO-DAY. I 1 3 

soaked in salt water, these experimenters showed that 

when the current from such a pile was passed through 

salt water, the water was decomposed and oxygen and 

hydrogen obtained in a free state. 

Shortly following this discovery Sir Humphry Davy,* 

This new fact still remains to be explained, and seems to point 
, to some general law of the agency of electricity in chemical oper- 
tions. As the distance between the wires formed a striking fea- 
ture in this result, it became desirable to ascertain whether it 
would take place to greater distances. When a tube three 
quarters of an inch in diameter, and thirty-six inches long, was 
made use of, the effect failed, though the very same wires, in- 
serted into a shorter tube, operated very briskly. The solicita- 
tion of other objects of enquiry prevented trial being made of 
all the various intermediate distances ; but from the general 
tenor of experiments, it appears to be established, that this de- 
composition is more effectual the less the distances between 
the wires, but that it ceases altogether when the wires come into 
contact." 

*The magnificent discovery by Davy of the compound 
nature of the alkalies and the alkaline earths is discussed 
by him in one of the Bakerian Lectures read on the 19th 
of November, 1807, and published in Vol. 98, of the 
Philosophical Transactions of the Royal Society of 
London for 1S08, on pa^e 2 : — 

u On the Method* used for the Decomposition of the 
]■'(>, ,/ AlhcU 

"The researches I had made on the decomposition of acids. 
and of alkaline and earthy neutral compounds, proved that the 
powers of electrical decomposition were proportional to the 

rength of the opposite electricities in the circuit, and to the 
conducting power and degree of concentration of the materials 
employed.' 1 

u In the first attempts, that I made of the decomposition <>f tha 



114 ELECTRICITY, 

on the 6th of October, 1807, made the immortal dis- 

fixed alkalies, I acted upon aqueous solutions of potash and soda, 
saturated at common temperatures, by the highest electrical 
power I could command, and which was produced by a combination 
of VOLTAIC batteries belonging to the Royal Institution, con- 
taining 24 plates of copper and zinc of 12 inches square, 100 plates 
of 6 inches, and 150 of 4 inches square, charged with solutions of 
alum and nitrous acid ; but in these cases, though there was a high 
intensity of action, the water of the solutions alone was affected, 
and hydrogene and oxygene disengaged with the production of 
much heat and violent effervescence." 

" The presence of water appearing thus to prevent any decom- 
position, I used potash in igneous fusion. By means of a stream 
of oxygene gas from a gasometer applied to the flame of a spirit 
lamp, which was thrown on a platina spoon containing potash, this 
alkali was kept for some minutes in a strong red heat, and in a 
state of perfect fluidity. The spoon was preserved in communi- 
cation with the positive side of the battery of the power of 100 of 
6 inches, highly charged ; and the connection from the negative 
wire was made by a platina wire." 

"By this arrangement some brilliant phenomena were pro- 
duced. The potash appeared a conductor in a high degree, and 
as long as the communication was preserved, a most intense 
light was exhibited at the negative wire, and a column of flame, 
which seemed to be owing to the developement of combustible 
matter, arose from the point of contact." 

" When the order was changed, so that the platina spoon was 
made negative, a vivid and constant light appeared at the oppo- 
site point : there was no effect of inflammation around it ; but 
aeriform globules, which inflamed in the atmosphere, rose 
through the potash." 

" The platina, as might have been expected, was considerably 
acted upon ; and in the case where it had been negative, in the 
highest degree." 

"The alkali was apparently dry in this experiment; and it 
seemed probable that the inflammable matter arose from its de- 
composition. The residual potash was unaltered ; it contained 



A HUNDRED TEARS AGO AND TO-DAY. I I 5 

covcry oi the compound nature of potassa, which had 

heretofore been regarded as an elementary substance. 

indeed a number of dark grey metallic particles, but these proved 
to be derived from the platina." 

"I tried several experiments on the electrization of potash 
rendered fluid by heat, with the hopes of being able to collect the 
combustible matter, but without success ; and I only attained my 
object, by employing electricity as the common agent for fusion 
and decomposition." 

"Though potash, perfectly dried by ignition, is a non-conduc- 
tor, yet it is rendered a conductor, by a very slight addition of 
moisture, which does not perceptibly destroy its aggregation ; 
and in this state it readily fuses and decomposes by strong 
electrical powers." 

"A small piece of pure potash, which had been exposed for a 
few seconds to the atmosphere, so as to give conducting power 
to the surface, was placed upon an insulated disc of platina, con- 
nected to the negative side of the battery of the power of 250 of 
6 and 4. in a state of intense activity ; and a platina wire, com- 
municating with the positive side, was brought in contact with 
the upper surface of the alkali. The whole apparatus was in the 
open atmosphere." 

"Under these circumstances a vivid action was soon observed 
to take place. The potash began to fuse at both its points of elec- 
trization. There was a violent effervescence at the upper sur- 
face ; at the lower, or negative surface, there was no liberation of 
elastic fluid ; but small globules having a high metallic lustre, 
and being precisely similar in visible characters to quicksilver, 
appeared, some of which burnt with explosion and bright flame, 
<>n as they were formed, and others remained, and were 
merely tarnished, and finally covered by a white film which 
formed on their surfaces.' 1 

U T: alee, numerous experiments soon shewed to be 

the SBbstance I was in -'-arch of. and a peculiar inflammable princi- 
ple the basis of potash. I found that the platina was in no way 
Beted with the result, except as the medium for exhibiting 
the electrical powers <>f decomposition ; and a substance of the 



1 1 6 ELECTRICITY, 

Davy showed that potassa consists of a hitherto undis- 

same kind was produced when a piece of copper, silver, gold, 
plumbago, or even charcoal were employed for compleating the 
circuit." 

" The phenomenon was independent of the presence of air ; I 
found that it took place when the alkali was in a vacuum of an 
exhausted receiver." 

"The substance was likewise produced from potash fused by 
means of a lamp, in glass tubes confined by mercury, and fur- 
nished with hermetically inserted platina wires by which the 
electrical action was transmitted. But this operation could not 
be carried on for any considerable time ; the glass was rapidly 
dissolved by the action of the alkali, and this substance soon pen- 
etrated through the body of the tube." 

"Soda, when acted upon in the same manner as potash, ex- 
hibited an analogous result ; but the decomposition demanded 
greater intensity of action in the batteries, or the alkali was re- 
quired to be in much thinner and smaller pieces. With the bat- 
tery of 100 of 6 inches, in full activity I obtained good results 
from pieces of potash weighing from 40 to 70 grains, and of a 
thickness which made the distance of the electrified metallic sur- 
faces nearly a quarter of an inch ; but with a similar power it 
was impossible to produce the effects of decomposition on pieces 
of soda of more than 15 to 20 grains in weight, and that only 
when the distance between the wires was about % or iV °^ an 
inch." 

" The substance produced from potash remained fluid at the 
temperature of the atmosphere at the time of its production ; that 
from soda, which was fluid in the degree of heat of the alkali dur- 
ing its formation, became solid on cooling, and appeared to have 
the lustre of silver.*' 

" When the power of 250 was used, with a very high charge for 
the decomposition of soda, the globules often burnt at the mo- 
ment of their formation, and sometimes violently exploded and 
separated into smaller globules, which flew with great velocity 
through the air in a state of vivid combustion, producing a 
beautiful effect of continued jets of fire." 



A HUNDRED YEARS AGO AND TO-DAY. 117 

covered metallic element, potassium, combined with 
oxygen, and, shortly afterwards, he extended this dis- 
covery and showed that nearly the entire crust of the 
earth, consisting ot various earths and alkaline earths, 
is similarly formed of metallic elementary substances 
combined with oxygen or other substances. 

The valuable discoveries following- the production of 
the voltaic pile did not stop here. In 1809, by em- 
ploying a powerful voltaic pile, formed of two thousand 
couples, Davy showed, at the Royal Institution in Lon- 
don for the first time on an extended scale, the intense 
light of the voltaic arc, which he established between 
two carbon sticks or electrodes. 

Although the arc light thus produced was by no 
means the first arc light,* yet it was perhaps the first 

* The light of the voltaic arc was known long before 
this. The first knowledge of the fact that a brilliant 
light is produced at a break in the circuit of a sufficiently 
powerful voltaic pile was known very shortly after the 
discovery of the pile. In Vol. II., page 200, of a publi- 
cation entitled : "The Collected Works of Sir Humphry 
•, " in a paper on "The ( )utlines of Galvanism/ 1 the 
following statement is made : — 

"When in a powerful battery (one for instance containing two 
hand:' s) the communication, after being broken, is again 

rendered complete, by the contact of two perfect conductors, a 
flash, or spark of li^ r ht is perceived, analogous to that produced 
by electricity. This spark, or flash, when the battery is most 
powerful, i- capable Of passing through a considerable stratum 
of air, and of inflaming mixtures of hydrogen and oxygen. When 



Il8 ELECTRICITY, 

time that it was publicly exhibited in such a manner as 
to demonstrate its possibilities as an artificial illumi- 
nant; and from this time up to a comparatively recent 

the me allic substances by which it is transmitted, are of very 
small volume, it is possessed of the power of igniting them ; and 
of making them enter into combustion when in contact with 
oxygen." 

I have experienced no little difficulty in tracing the 
early history of the first carbon arc obtained by the use 
of the voltaic pile. Nearly all writers ascribe such arc 
to the battery of two thousand couples of the Royal 
Institution, but, beyond any doubt, Davy and others had 
demonstrated the existence of the voltaic carbon arc 
before this date. 

On page 21 1 of the same Vol., in a paper entitled "An 
Account of Some Experiments on Galvanic Electricity 
made in the Theatre of the Royal Institution " the fol- 
lowing account is given : — 

" The apparatus employed in these experiments was composed 
of 150 series of plates of copper and zinc of 4 inches square, 
and 50 of zinc and silver of the same size. The metals were 
carefully cemented into four boxes of wood in regular order, 
after the manner adopted by Mr. Cruickshank, and the fluid 
made use of was water combined with about 1/100 part of its 
weight of nitric acid." 

" The shock taken from the batteries in combination by the 
moistened hands, was not so powerful but that it could be 
received without any permanently disagreeable effects. Charges 
were readily communicated by means of them to coated jars, and 
to a battery ; but in this case the effects produced by the elec- 
tricity were much less distinct than in the case of immediate 
application." 

"When the circuit in the batteries was completed by means of 



A HUNDRED YEARS AGO AND TO-DAY. IIQ 

><1. many futile attempts were made to successfully 
employ it as an artificial illuminant As we all know 
this problem has at last been successfully solved, and 
-ful arc lighting; is an established fa 

small knobs of brass, the spark perceived was of a da. 
brightness, and in apparent diameter at least h ; of an inch. It 
was perceived only at the moment of the contact of the metals, 
and it was accompanied by a noise or snap." 

u When instead of the metals, pieces of well-burned charcoal 

were employed, the spark was still Larger and of a vivid white- 

.n evident combustion was produced, the charcoal remained 

red hot for some time after the contact and threw off bright eor- 

ruscations." 

•• Four inches of steel wire 1 170 of an inch in diameter, on 
wd in the circuit became intensely white hot at the 
point of connection, and burnt with izreat vividness being at the 
same time red throughout the whole of their extent." 

" Tin. lead, and zinc, in thin shavings were fused and burnt 
at their points of contact in the circuit, with a vivid light and 
with a loud hissing noift a blue flame, tin a purplish, 

and lead a yellow rlame violet at the circumference." 

M When copper leaf was employed it instantly inflamed at the 

green light and vivid sparks, and became red hot 
throughout the whole of its diameter when it did not exceed four 
inch 

S .\er leaf g ivid light, white in the centre and g 

towards the outliue. with red sparks or eorruseations. Platina 
in thin slips, when made to complete the circuit, became white 
hot. and entered into fusion, and gave scintillations at the 
it whether any part was converted into oxyde could not 
be accur;. 

. attached by gum-water to white papei was 

burn' rk, the li_ <»f a bright yellow and the 

y loud : the gold was converted into an oxydfi 

of purpli>h brown c<»l«»ur. which tinnly adhered t«> t|i,. paper, and 



1 20 ELECTRICITY, 

by regulating the course of the spark by means of the commu- 
nicating wire, letters and figures were traced by the combustion, 
which appeased semi-transparent when exposed to the light." 

" When the galvano-electric spark was taken by means of two 
pieces of charcoal partially covered with cotton, the cotton was 
readily inflamed ; whether in its simple state, or sprinkled over 
with resin or sulphur." 

"Fulminating mercury and gunpowder were deflagrated by 
means of the communication of charcoal ; and hydrogen and the 
compound of inflammable gases, were readily made to burn when 
simply in contact with the atmosphere and to detonate when 
mixed with oxygen." 

" A few only of these results have any claim to originality. On 
the phenomena of the combustion of bodies by galvanism we 
have been already furnished with many striking experiments, 
by our own countrymen, and by the German and French philos- 
ophers. And after the path is once discovered in researches of 
this kind, to pursue it requires but little ability or exertion. 
An account of common facts, under new circumstances, partic- 
ularly when they are accompanied by striking phenomena, can 
however never be wholly useless ; and it sometimes gives a novel 
interest to the subject, and tends to awaken curiosity." 

It would appear from Davy's remarks at the end of 
the above quotation that he does not claim to have first 
discovered the brilliant effects of the electric arc light. 
The arc produced by the voltaic pile of 2,000 couples of 
the Royal Institution was different from prior arcs merely 
in degree of splendor. The phenomenon itself had be- 
fore been well known. 

This experiment of Davy is thus referred to by 
George J. Singer on page 405, of his "Elements of Elec- 
tricity and Electro-Chemistry," published in London in 
1814. 

"With a large apparatus employed at the Royal Institution, 
which extends to 2,000 pairs of four-inch plates, points of char- 
coal were brought within a thirtieth or fortieth of an inch of 



A HUNDRED YEARS AGO AND TO-DAY. 121 

each other before any light was evolved : but when the points of 
charcoal had become intensely ignited, a stream of light con- 
tinued to play between them when they were gradually with- 
drawn even to the distance of near four inches. The stream of 
light was in the form of an arch, broad in the middle and 
tapering towards the charcoal points; it was accompanied by 
intense heat, and immediately ignited any substance introduced 
into it ; fragments of diamond, and points of plumbago disap- 
peared, and seemed to evaporate, even when the experiment 
was made in an exhausted receiver ; though they did not appear 
to have been fused. Thick platina wire melted rapidly, and fell 
in large globules ; the saphire, quartz, magnesia, and lime, were 
distinctly fused. 

In rarefied air, the discharge took place at a greater distance, 
and the beam of light was made to pass through an interval of 
or seven inches.' 1 

Another description of this experiment is thus given 
on page 463 of Vol. ^. of the Philosophical Magazine, 
bv Alexander Tilloch, published in London in 18 10 : 

'•In the concluding lecture at the Royal Institution, the large 
Voltaic apparatus, consisting of two thousand double plates of 
four inches square, was put into action for the first time. The 
effects of this combination, the largest that has ever been con- 
structed, were, as might have been expected, of a very brilliant 
kind." 

"The spark, the light of which was so intense as to resemble 
that of the sun. struck through some lines of air. and produced a 
:rge through the heated air of nearly three inches in 
.. and of a dazzling splendour. Several bodies which had 
not I by this flame : the new- 

metals disOOTered by Mr. Tennant. iridium, and the alloy of 
iridium and osmium. Zircon and alumina were likewise fused; — 
charcoal was made t.«» evaporate, and plumbago appeared to fuse 
in vacuo. gnited to intense whiteness by it in 

oxymuriatic ac ad volatilised in it. but without effecting 

•mii. A large Leyden battery, containing 24 coated 
van discharged by a momentary contact of the wires to a 



122 ELECTRICITY, 

degree that required from 20 to 30 turns of Nairne's electrical 
machine of eight inches diameter. All the electrical phenomena 
of the passage of electricity to a distance ; the discharge through 
a Torricellian vacuum ; the attractions and repulsions of light 
bodies, were demonstrated in a distinct way by means of this 
apparatus . It may be hoped that the application of so powerful 
an instrument, and such easy methods of producing the most 
intense heat, will lead to some new facts in analytical science." 

This battery of two thousand cells was the one with 
which Davy at a later date made his investigations as 
to the effects produced on the voltaic arc by means of a 
magnet. He thus describes the effect on page 407 of 
Vol. II. of the Philosophical Transactions for 1821 : 

"Mr. Pepys having had the goodness to charge the great bat- 
tery of the London Institution, consisting of two thousand 
double plates of zinc and copper, with a mixture of 1168 parts 
of water, 108 parts of nitrous acid, and 25 parts of sulphuric 
acid, the poles were connected by charcoal, so as to make an 
arc, or column of electrical light, varying in length from one to 
four inches, according to the state of rarefaction of the atmos- 
phere in which it was produced ; and a powerful magnet being 
presented to this arc or column, having its pole at a very acute 
angle to it, the arc, or column, was attracted or repelled with a 
rotary motion, or made to revolve, by placing the poles in dif- 
ferent positions, according to the same law as the electrified 
cylinders of platinum described in my last paper, being repelled 
when the negative pole was on the right hand by the north pole 
of the magnet, and attracted by the south pole, and vice versa." 

"It was proved by several experiments that the motion de- 
pended entirely upon the magnetism, and not upon the electrical 
inductive power of the magnet ; for masses of soft iron, or of other 
metals, produce no effect. The electric arc or column of flame 
was more easily affected by the magnet, and its motion was 
more rapid when it passed through dense than through rarefied 
air ; and in this case, the conducting medium or chain of aeri- 
form particles was much shorter." 



A HUNDRED YEARS AGO AND TO-DAY. I23 

"I tried to gain similar results with currents of common elec- 
tricity sent through flame, and in vacuo. They were always 
affected by the magnet ; but it is not possible to obtain so de- 
cided a result as with Voltaic electricity, because the magnet itself 
became electrical by induction, and t hat whether it was insulated, 
or connected with the ground." 

But it would far exceed the limits of this little book 
to trace here the many unsuccessful efforts that were 
made to brin^r about a commercial introduction of the 
arc light At various intervals in the progress of elec- 
tric science, it was believed that the time had at last 
come for the successful solution of the problem. Public 
expectation was aroused and more or less extensive 
trials made, but the conditions were not all fulfilled 
and that inevitable failure resulted, which, must per- 
force, attend all attempts in which any single condition 
remains unfulfilled. 

Many attempts were made to operate such lights by 
means of voltaic batteries. Mr. Grove, who was among 
the experimenters in this direction, gives the following 
summary of his experiments on page 210, of Vol. 50, of 
the Mechanics' Magazine, published in London in 1849 : 

"Mr. Grove made some experiments six years ago on the sub- 
ject, and then on one occasion delivered a lecture at the London 
Institution, when the theatre was illuminated by the voltaic arc. 
In preparing the present lecture, lie had made a rough calcula- 
tion as to its expenses, and the matter appeared to him (though 
attended with many practical difficulties) to be hopeful and 
promising. By interposing a voltameter in the circuit while the 
arc was produced, the oonsnmptioo in the battery could be cal- 
culated; for every chemical equivalent of hydrogen evolved in 
the voltameter an eqnivalenl of zinc, of sulphuric acid, and one- 
third of an eqnivalenl of nitric acid would be consumed i'i each 
cell of the battery. Supplying these data U>v calculation, and 
making proper allowance for the amount Of water contained in 



I 24 ELECTRICITY, 

the commercial acids, &c, the theoretical expense of a battery 
such as he was exhibiting (fifty cells of the nitric acid combi- 
nation, each platinum plate two inches by four) would be about 
two shillings per hour." 

" He had tested by the photometric method of equality of 
shadows the intensity of the light as compared with a common 
wax candle, and fouud that after the battery had been an hour at 
work, the voltaic light was to the candle as 14-U: to 1. He did not 
take this comparison of intensities as an absolutely fair practical 
comparison, nor did he give the above as a practical calculation, 
but thought it would be safe if twice that expense, or four shil- 
lings per hour, were assumed ; the actual expense of charging 
the battery for a given time of action bore this out. He showed 
the inferiority of central as compared with separate lights for 
street illumination ; but for light-houses, particularly for an in- 
termittent light at regular intervals, or for signal lights, the ap- 
plication appeared to him to be reasonably approximate, and 
for more general purposes, far from hopeless — the practical 
difficulties, though undoubtedly not small, being, in his opinion, 
by no means insurmountable.'' 

In the same direction is the following description on 
page 271, Vol. 51 of the same magazine: 

THE ELECTRIC LIGHT. 

Paper read on the comparative cost of making various Voltaic 
Arrangements. By Mr. W. S. Ward. 

81 The author stated that a series of calculations founded on 
data, produced to the Chemical Section at Swansea, showed the 
efficient power of three generally-used forms of batteries known 
as Smee's, Daniell's, and Grove's, would be equal, when 100 pairs 
of Smee's. 55 pairs of Daniell's. or 31 pairs of Grove's were used, 
and that the expense of working such batteries as regards a 
standard of 60 graius of zinc in each cell per hour, would be 
about 6d., "M., and 8cL, respectively." 

" This communication led to conversations on the economy of 
the electric light and electro-magnetic engines, in which Dr. 
Faraday, Mr. Shaw, Mr. Hunt, Mr. Elkington, and other gentle- 



A HUNDRED YEARS AGO AND TO-DAY. 1 25 

men joined. Dr. Faraday remarked on the imperfect character 
of electric light, and its inapplicability for purposes of general 
illumination ; all objects appearing dark when the eye was 
embarrassed by the intensity of the electric arc. Mr. Shaw and 
Dr. Percy instanced the magneto-electric machines which are em- 
ployed at Birmingham for electro-plating, in which the current 
cost of the motive power, viz.. a steam engine to put the mag- 
neto-electric machine in action, was the only working cost. Mr. 
Elkington stated that they had never been induced to abandon 
the voltaic battery which they employed in their manufactory, 
finding it more economical than the magueto-electrical machine of 
which he was the patentee. He also stated the remarkable fact, 
that a few drops of the sulphuret of carbon added to the cyanide 
of silver in the decomposing cell, had the property of pre- 
cipitating the silver perfectly bright, instead of being granulated 
so dead as it is when thrown down from the solution ordinarily 
employed." 

Perhaps one of the ablest pioneers in the direction 
of the commercial introduction of the arc light was 
Staite. He invented a number of very creditable arc 
lamps, but necessarily failed of success on account of 
the non-existence of a sufficiently cheap electric source. 
The following interesting account of his experiments is 
quoted from page 411, of Vol. 54, of the Mechanics' 
Magazine : 

"The public curiosity has been much excited to be made 
acquainted with the report of the committee who were appointed 
so far back as August to inquire into the adaptation of this 
light for general illumination. The Committee having termi- 
nated their labours, the 9th ir.st., was the first time the exhi- 
bition took place of the apparatus, constructed with a view of 
testing the self-su<taining power of the mechanical arrangement 
adapted for the continued development of the Light, the sus- 
tains _ <>f the battery, and the cost of the whole. Tt was 
understood th? ie experiments we: trough on this 
re required by the Committee, and parties in the 



126 ELECTRICITY, 

room volunteered to keep accurate registers of the effects pro- 
duced. The Company, among whom we recognized several 
members of the Committee, were invited for half-past three, 
shortly after which the battery was charged, and at four the 
light was set in action, it being understood that it was to burn 
for five hours and a quarter without interruption, that being the 
period at which the Committee had expressed themselves satis- 
fied that it could be continued for any definite length of time. 
The Rev. St. Vincent Beechey of Worsley, took charge of the 
photometrical arrangement, by which the comparative power of 
the light was ascertained, and we observed Mr. Daniel Stone, 
jun., attending to the means adopted for measuring the electric 
power passing. The light continued to burn with increasing 
brilliancy from four o'clock to six, giving successively a light, ad- 
judged equal, the first half-hour, to 200 candles ; at five, to 300 ; 
at half-past five, to 400 ; and so successively till the electric fluid 
came into its fullest action at half-past six ; when the light, by 
the instrument used, — which we heard had been borrowed for 
the purpose from Mr. Cleminshaw, of the gas-works, — developed 
the immense number of 700 candles ; which intensity of light 
was steadily kept up till the experiment concluded at a quarter- 
past-nine o'clock. By way of passing the time, and amusing 
the parties assembled, many of the experiments were given 
which had previously excited so much interest at the Town Hall ; 
and it being perfectly light at the commencement of the experi- 
ment, and the sun shining, gave the opportunity of bringing 
coloured prints from the influence of the direct sunbeam to that 
of the ray from the electric light, in which not the slightest dif- 
ference of shade of colour could be observed. The light of each 
was then passed through the prism, which still further estab- 
lished their identity, as their point of junction could not be as- 
certained, — thus proving its immense value to the manufacturer 
and exhibitor of goods. The light was then attempted to be 
diffused over the room, by means of lens, generally used in 
French lighthouses, and known as the Fresnell Lens, from the 
name of its inventor ; but as the room was only some 120 feet 
long, and the Fresnell Lens is calculated to act on an area of 
a mile no effect was produced beyond enabling us to imagine 



A HUNDRED YEARS AGO AND TO-DAY. 1 27 

the possibility of so adapting it. The mode adopted by the 
English by means of a parabolic reflector, which condenses 
the light in one direction, was then exhibited ; and certainly 
the effect produced was sufficient to make us believe the 
statement, that at Sunderland the Commissioners were able 
to read at a distance of more than three miles at sea. The 
time having arrived at which the exhibition had been in- 
tended to close, before the company separated, a portion of the 
solutions produced by the action of the battery were drawn off 
and precipitated before the company present, and a white powder pro- 
duced, which was represented to be of a commercial value sufficient 
to pay the whole expense of producing the light or of that even- 
amusement. Of course, in the absence of the Report of the 
Committee it would be impossible for us, merely attending in 
the capacity of spectators, to pledge ourselves for anything more 
than we saw — we do not presume to be any judges of the value 
of these residues, nor to the precise amount of light developed, 
but it certainly is a most extraordinary amount of light ; and the 
parties in the room — and we are not alluding to Mr. Staite, or any 
one apparently connected with him — stated with confidence the 
amount of candles to which it was equal ; but if this light can be 
maintained for anything like a reasonable cost, its power of dis- 
tinguishing colours by night as well as by day, and total absence 
of any heat, or contamination of air, renders it one of the most 
useful inventions on record." 

The ingenious reference to the commercial value of 
the products obtained by the chemical action in the 
battery are strikingly suggestive of the glowing ac- 
counts of certain primary batteries of our own days. 

When the brilliant discoveries of Faraday in the 
domain of n electric induction finally led to the 

production of the magneto-electric machine, it was 
again believed that the problem of a commercial 
electric light was solved. 

A certain Mr. Paine created no little excitement in 
this direction. Ili.^ plan appears to have been to em- 



125 ELECTRICITY, 

ploy a magneto-electric machine for the decomposition 
of water and to employ the gas so generated to produce 
the lime or oxyhydrogen light. Judging from the ex- 
planations given by the inventor of some of the details 
of his invention he failed signally, in many respects, to 
understand just what he was doing. I give these quo- 
tations rather fully, however, because they show the 
public interest in electric lighting at this early 
date. 

The following accounts of Mr. Paine's discoveries are 
taken from Vol. 54, page 68, of the Mechanics' Maga- 
zine : 

"What we have seen enables us to say, not only that Mr. Paine 
has extorted from nature the secret of the artificial production of 
light at a nominal cost, but that he has got hold of the key which 
unlocks and enables him to command a new force of nature, 
which is soon to supersede most of the forces now employed — 
something which is destined to work a revolution both in science 
and art." 

"The operation, as we saw it, was as clear and clinching a 
demonstration as we ever witnessed in the range of chemical 
science. There was a rapid and abundant evolution of gas from 
the water in the jar, with which nothing whatever communicated 
save two flat strips of copper and the small tube which termin- 
ated in the jet or burner, without any possible connection with 
anything between the jar and burner, save the spirits of turpen- 
tine contained in another smaller glass j ar. The electric apparatus 
being put in motion, as soon as the air over the water had been 
expelled, and the exit was closed, the pressure over the water 
drove the gas rapidly through the spirits of turpentine, and the 
jet beyond it being lighted, burned freely and with a high illu- 
minating power. A jet attached to the tube between the jar of 
water and of spirits of turpentine, was lighted, and we saw the 
unrnistakeable form of hydrogen, scarcely visible by daylight. 
This pure hydrogen was the gas evolved from the water, and 
could not possibly have come from the turpentine, for the cur- 






A HUNDRED YEARS AGO AND PO-DAY. 120, 

rent was all tho time flowing From the water through the spirits of 

turpentine and how eoold the spirits o\ turpentine give an illu- 
minating flame on one side and the invisible tlame on the 
other r 

u Here, then, whatever may be the agency exerted on the water, 
by or through the tlat ribbons o\' copper, be it something or 
nothing— whether we understand it or Cn^ not understand it — 
water is first converted into hydrogen, or some invisible burning 
Lras, and then, having passed through spirits of turpentine, into 
a gas of very luminous tlame." 

Bo far as light is concerned, here it i>. Mr. Paine produces 

it somehow, and does it abundantly. There is no rubbing this out, 
audit is unpardonable in the 'scientific men* who must have 
seen it, that they were unwilling to acknowledge it that they 

omitted a portion of the demonstration, and so left the public to 
infer the power and agency of other causes to account for the 
effect ! ■ 

M We DOW come to the question of the cost. Mr. Paine showed 
us every part of his apparatus, including his peculiar helices and 
Ee, not shown to the scientific men before mentioned. We 
are not at liberty to explain to our readers the peculiarity of 
their construction : sulliee it to say. they elucidated the subject 
much to our mind, and clothed the discovery with scientific inter- 

superior to it- economical and practical.' 1 

''The means by which Mr. Paine exerts an agency upon the 
water through the copper ribbons, is of electro-magnetic 

condenser — an instrument different from those manufactured by 
the electro-magnetic instrument mak< ra in this city, only in the 
interior construction of its revolving helices. It consists <^\ two 
permanent, horse-shoe mau r net<. parallel and open- 
ing in the same direction, between the poles of which a pair of 
helices are made to revolve horizontally. There is no galvanic 
action in I stever on these helices but 

of the slight mechanical force which is accessary to give them a 
moderately rapid revolution, they meeting no resistance but that 
of a common pivot and the slight friction of their poles upon 
metallic discs * But t be |- 

of this simple arrangement to evolve electricity is tremendous. 
<>t note page 



I30 ELECTRICITY, 

The electrical force compared with the mechanical cause, is like 
that of the rush of water which carries the wheel of a great cotton 
factory compared with the effort of a child who may hoist the 
gate. At each discharge of the helices, and there are many in a 
second, according to the rapidity, an abundant crop of gas 
bubbles is produced : and this is owing partly to the peculiar 
construction of the electrode, or form of the poles where pre- 
sented in proximity to each other in the water of the jar. 
This electrode is a point of great interest, and it is just at 
this point that the mighty and mysterious fluid, so potently com- 
manded and propelled by helices, may prove too big for its busi- 
ness, and show its relationship to the favorite weapon of Jove. 
Here is a stupendous difficulty which has tasked the courage and 
inventive genius of Mr. Paine — a difficulty of which the public 
could not be aware, and which seems to account for much delay. 
He has tamed the thunderbolt in this delicate point, at least so 
far as to insure perfect safety with due care. Other safe-guards 
may yet be added. However, it is but right to say, that it 
would not be strange if carelessness and temerity should here- 
after meet with a fate here — that would be a caution to them." 

" The next question is, whether there is any expense of the 
spirits of turpentine. We certainly could not discover, while we 
watched it, the slightest waste or diminution. Mr. Paine, and 
others testify, that there is no expenditure of that material. The 
nature of the luminous flame convinced us that it had gained 
nothing in quantity, only something in quality, from the spirits 
of turpentine ; and this hypothesis, as any booked-up chemist will 
admit, is nothing unprecedented. In " Stockhard's Chemistry," an 
excellent work, we find the following — page 473 : 

" Starch, as shown by these exp3riments, is converted by sul- 
phuric acid, on moderate heating into gum; on stronger heating, 
into sugar. In the latter case, also, dextrine is first formed, but 
this soon passes over into sugar. Accordingly, sulphuric acid 
exerts two different actions. By the first action, the starch 
becomes gum (dextrine). By the second action, the dextrine be- 
comes sugar." 

" It has not yet been explained how this effect was produced. 
Starch, starch-gum, and starch-sugar have each the same con- 



A HUNDRED YEARS AGO AND TO-DAY. I3I 

stitution (isomeric.) so that their difference undoubtedly depends 
upon a different arrangement o( the atoms of carbon, hydrogen, 
and oxygen contained in them, and it is undoubtedly the sul- 
phuric acid which effects this change in the position of the 
atoms." 

u Then, again; after a man has, with his own eyes, seen water 
converted into hydrogen, and nothing else unless the oxygen 
goes off through the solid copper ribbon of the positive pole into 
a cup of water, and is there drowned without a sign or a bubble 
— we say, after a man lias seen this transformation of water, so 
unauthorized by the books, it will not be very incredible to him 
that the spirits of turpentine may change the quality — the elec- 
trical state — arrangement of particles, or whatever you may sup- 
pose it — in the hydrogen, without imparting anything whatever to 
it. This, we must say, is what we are strongly inclined to believe 
that it does. On the whole, we feel confident that Mr. Paine has 
discovered the means of producing an inexpensive light of the 
purest and most efficient quality, and opened a new and vast 
tield in science. "We have seen for ourselves, and find that we 
have done Mr. Paine very great, though not intentional, injustice. 
And we can hardly find words to express our surprise at the 
Scientific Report, which was partly the cause of our doing so. 
The demonstration which Mr. Paine then presented could not 
have been of a doubtful character to chemical eyes. Those gentle- 
men must have understood and believed more than they 
reported.*' 

So also on pag-e 114 of the same volume: 

"Mr. Paine commenced turning the wheel in the Magneto 
Electric Machine, and we all looked to see the gas arise from the 
trades in the jar of water, but no gas appeared. At length 
Mr. Ames discovered that one of the wires or copper ribands had 
been detached, or had not been screwed on to the wire at the top 
of the bell-glass." 

"This being corrected, Mr. Paine again commenced turning 
the machine, and Instantly large bubbles of gas arose from the 
electrode-, and filled the jar in less f/i<i>i <i minute! After taking 
out a Btoppei from the bell-glass, and allowing several jars-fuU 



\- 



El ECTRICITW 



of gas to escape, in ore >el the common air, and pv 

kd ox plosion, these we w gas rough 

the gaspipe into the turpentine ; and through this to the jet or 
burner* Between the jar of water where the gas was generated 
and the jar of turpentine, a jet issued from the pipe. Th 
lighted, and proved to be h J - The flame, in front of 

a window* was so pale that it could n< ceived* We could 

putting a dark body behind it* While th> ning, 

the gas was forced along through the turpentine to the other 
burner, A flame was applied to this, and a brMtiant tight teas 

&&WM P ' 

""Here were two flames burning at the same time, from 
saiv; gas ::ie first* be' ^ng through the tur pent: 

burned with a pale> almost imperceptible light* — the second, after 
passing through the turpentine, burning with a light superior to 
any gas that t ever saw before* When the magnetic machine 

is si opped, not a bubble of gas would appear in the jar, and the 
lights went out* This small machine genet;- ^h to 

supply a dozen burners. one Q * hich I should think sufficient 

to light a room*** 

n aw, it will natural. isked oould not this tremendous 

electrical power which decomposed the water, ned from 

some other source than the magnetic machine ?* This qu« 
occurred to me before I saw the operation ; and I determined* if 
possible, to Si? myself upon the subject* I, therefore, with Mr* 

Paine*s full permission, examined the table. I could easily see t 
no wires or pipes entered the glass jar of w - p| the ta 

connected with the magnetic machine. It was* therefore. 
magnetic machine that my attention was mainly directed* This 
machine I took up, and lifted it entirely away from the table — 
saw that no wires* pipes, or metallic substances whatever had any 
connection with it from the table* I placed the machine , 
on the table and turned the crank* and produced the gas in 1 
jar, in the same manner and with the sam e success : hat Mr* 
had done. Mr* Ames and Mr* Merrick did the same* and v. 
all satisfied : iwf&ctHy satisfied that th& omtw mas dtwmpo&ed 6jf 
tifoe <e$@dti> n mtyflwm tike ma&mtte maekma, and nowher* <els<?* To deny 
this, we must deny the evidence of our own senses* The gas was 



\ HUNDRED vi IRS IGO \M> TO-D w. 

also prod thousan a thousand times, 

than • Lmilar apparatus ! We 

had also I SD.C6 that t lie gas, 'i 1 1 • 

through turpentine, furnished a brilliant Light. The ^ r as pro- 
be hydro Judged by the smell and the 
burning : and aUthowjh he called if hydro- 
q )i g dUmary hydro / i .. [ ae ked Mr. 
j he interrupted the positive pole i»\ the glass of water 

two, and placed the ends in the glass of 

id that mil. is done, both hydrogen and 

I : .- rated in the bell glass : but that )>>■ this 

only obtained the hydrogen. There appeared to be no 

by the operation-* 1 

u \ amount of turpentine consumed by passing the 

:\\ it. it was impossible for as to determine in the short 
;m hour : ■ rating and burning the 

that the gas was not carbonized, hut was 
£ through the turpentine, and th oloss 

ral gentlemen of high 
lays previous to our visit, pur- 
si] quantity of turpentine, measuring it 
rich they took to Mr, Paine's establishment, and 
roduced by thi of magnets, through it 

.1 hours, ' tole of Mi. Paine's house. The 

at t he filOSe, and found to h;ive 

ttful only as much a< would be lost by evap- 
ruing it • 

fl have frequently met with equal f ■ the 

a mam . amining 

a [2-light dynan liine with a view <>i 

it into 1 He \, 

■ 
it, he had no 
fairly J [< I tliat he had a 



134 ELECTRICITY, 

The discovery of the arc light though mature was un- 
ripe ; for neither the proper lamps were invented, nor, 
what is more to the point, had efficient commercial 
means for developing electricity yet been produced. 

It was not until the immortal Faraday conducted that 
magnificent line of experiments between 183 1 and 1832, 
on the means for producing electricity directly from 
magnetism, that the road was opened for the production 
of a new electric source in the dynamo-electric machine. 

It is interesting to note the manner in which several 
great inventions often go hand in hand, and how 
immature inventions that have long ago been made 
and forgotten, become ripened and called into active 
life by subsequent inventions that supply or fill out 
some points that the prior inventions lacked. For ex- 
ample, I have already called your attention to the fact 
that as soon as it was known that electricity transmitted 

small y 2 horse power engine he used for small work, 
and did not doubt but that he could get the number of 
revolutions required from the engine in addition to the 
work for which he generally employed it, and when I 
assured him that he would need at least 10 horsepower, 
or more, if he desired to run the machine for 1 5 arc 
lights, he was indignant that I should ask him to believe 
such a statement. 

f An excellent illustration of the saying, so true in all 
domains of thought but especially so in the domains of 
scientific thought, "A little knowledge is a dangerous 
thing." 



A HUNDRED TEARS AGO AND TO-PAY. 1^5 

> practically instantaneously through conduct 
ing- paths, inventors were not wanting 
agent as a means for telegraphic communication be- 
tween distant points. In such suggestions we find 
the germs of the modern telegraph. 

But the invention iA' a feasible system oi telegraphy 
ssible until at least two other discoveries had 
: namely, that of the electro-magnet by Stur- 
:; <>r by Henry* in 183 . and that by 
liell, in I J stanl lie pile or bat;. 

The peculiarity in which Daniell's I 1 differed 

be found in the fact that it is capable 
for prolonged times an approximately con- 
current. 

♦The ssil >f developing great magnetic power 

fas tic battery, is thus - xibed 

Henry on page 4cc\ oi VoL 19 of Silliman's 

an Journal S nee and Arts," for Jan;. 

ilUplier to 

: by 

Pi < 

" F< g time after th< ry of the principal facts in 

electro-mau r neti-m. the experiments in this interesting department 

d only by those who were bo fortu- 
re galvanic apparatus. 
1 ch. did mnefa La making the 

Uy kiKiwn. by shewing that when powerful 

perimentfl 
can be performed with a very small galvanic combination. Hlfl 



136 ELECTRICITY, 






articles of apparatus, constructed on this principle, are of a much 
larger size, and more convenient, than any before used. They 
do not, however, form a complete set, as it is evident, that strong 
magnets cannot be applied to every article required, and par- 
ticularly to those intended to exhibit the action of terrestrial 
magnetism on a galvanic wire, or the operation of two galvanic 
wires on each other." 

" In a paper, published in the Transactions of the Albany In- 
) stitute, June, 1828, I described some modifications of apparatus, 
intended to supply this deficiency of Mr. Sturgeon, by introduc- 
ing the spiral coil on the principle of the galvanic multiplier of 
Prof. Schweiger, and this I think is applicable in every case 
where strong magnets cannot be used. The coil is formed by 
covering copper wire, from ^ to ^0 °f an mcn in diameter, 
with silk ; and in every case, which will permit, instead of using 
a single conducting wire, the effect is multiplied by introducing 
a coil of this wire, closely turned upon itself. This will be readily 
understood by an example : thus, in the experiment of Ampere, 
to shew the action of terrestrial mngnetism on a galvanic cur- 
rent, instead of using a short single wire suspended on steel 
points ; 60 feet of wire, covered with silk, are coiled so as to form 
a ring of about 20 inches in diameter, the several strands of 
which are bound together by wrapping a narrow silk ribbon 
around them. The copper and zinc of a pair of small galvanic 
plates are attached to the ends of the coil, and the whole sus- 
pended by a silk fibre, with the galvanic-element hanging in a 
tumbler of diluted acid. After a few oscillations, the apparatus 
never fails to place itself at right angles to the magnetic merid- 
ian. This article is nothing more than a modification of De la 
Rive's ring on a larger scale." 

"Shortly after the publication mentioned, several other ap- 
plications of the coil, besides those described in that paper, were 
made in order to increase the size of electro-mangnetic appara- 
tus, and to diminish the necessary galvanic power. The most 
interesting of these, was its application to a developement of 
magnetism in soft iron, much more extensively, than to my 
knowledge has been previously effected by a small galvanic 
element." 






A HUNDRED YEARS AGO AND TODAY i;~ 

" A ronnd piece of iron, about y of an inch in diameter, 
bent into the usual form of a horse-shoe, and instead of loosely 
coiling around it a few feet of wire, as is D€ H was 

tightly wound feet of -:1k, so as 

to form about 400 turns : a pair of small galvanic plates, which 
could be dipped into a tumbler of diluted acid, was a . red to 
the ends of the wire, and the whole mounted on a stand. With 
these small plates, the horse-shoe became much more powerfully 
than another of the same size, and wound in the 
usual manner, by the application of a ba* 

9 of copper and zinc, each 8 inches square. Another 
convenient form of this apparatus was co: y winding 

.ight bar of iron 9 inches long with 35 feet of wire, and 
supporting it horizontally on a small cup of copper containing 
a cylinder of zinc, when this cup. which served the double pur- 
of a stand and the galvanic element, was tilled with dilute 
acid, the bar became a portable electro-magnetic magnet. These 
articles were exhibited to the Institute in Mar 

•■ The idea afterwards occurred to me. that a sufficient quan- 
tity of galvanism was furnished by the two small plates, to de- 
velope, by means of a coil, a much greater magnetic power in 
a larger piece of iron. To test this, a cylindrical bar of iron, l * 
an inch in diameter, and about 10 inches long, was bent into the 
form of a horse-shoe, and wound with 90 feet of wire ; with a pair 
of plates containing only 2 l 2 square inches of zinc, it lifted 1 + 
lbs. avoirdup< same time, a very material improve- 

ment in the formation of th gg • d itself to me. on read- 

more detailed account of Prof. Schweij 'a _ . morneter. 
and which was also tested with complete - :pon the - 

- -hoe : it I in using several strand- of wire, each 

covered with silk, instead of jreeably to this construction, 

nd wire, of the same length as the first, was wound over it, 
and the ends soldered to the zinc and copper in such a manner 
that the galvanic current might circulate in the same direction 
in both, or, in other words, that the two wires might act as 
the effect by this addition was doubled, as the Imrse-shoe, with the 
same pla' i, now supported 2811m 



I jS ELECTRICITY, 

11 With a pair of plates I Inohes by <*», it, Lifted 89 lbs., or more 
than - r >o times Its own weight." 

"These experiments conclusively proved thai a great develops- 
ment of magnetism oould be effected by a very small galvanio 
element) and also that the power of the obi] was materially in- 
creased by multiplying the number of wires, without inoreasing 
the Length of eaoh, 

"The multiplication of the wires, Increases the power in two 
ways ; first, by conducting a greater quantity of galvanism) and 

seoondly, by ^ivin^ it, a more proper direction, for since the ac- 
tion of a galvanio ourrent is direotly at eight angles to the axis 
of a magnetic needle, by using several shorter wires, we can wind 
one on each inch of the Length of the bar to be magnetized, so 
that the magnetism of eaoh inch will be developed, by a separate 

wins in this way the action of each particular coil beoomes very 

nearly at right angles io the axis of the bar, and consequently, 
the effect Is, the greatest possible. 'This principle is <^\' muoh 
greater Lmportanoe when Large bars are used. The advantage 
of a greater oonduoting power from using several wires might 

in a less degree be obtained by substituting for them one Large 

wire of equal seotional area, but, in this oase the obliquity of the 
spiral would be much greater and consequently the magnetic 

action less ; besides this, the effeot appears to depend in some 

degree on the number of turns which is much increased by using 
a number of small wires." 

" In order to determine to what extent the coil oould be ap- 
plied m developeing magnetism in soft iron ; and also to ascer- 
tain, if possible, the most proper Length <>( the wires to be used 

"A series of experiments were instituted jointly by Dr. Philip 
Ten Kyck ami myself. For this purpose L060 feet (a little more 

than I of a mile) of copper wire of the Kind Called bell wire, 

.046 (yJ8o) of an inoh in diameter, were stretohed several times 

across the Large room of the Aeadein y." 

4k Eccpertmmt /. A galvanic current, from a single pair of plates 
of oopper and eino i' inohes square, was passed through the whole 
length o^' the wire, and the effeot on a galvanometer noted ; 

From the mean of several observations, the deileetion oi the 

needle was IS ." 



- DAY. 

::rriit From t ho saino plan- 1 

through ball the a! . the deft 

in this instanoi was tl c ." 

In the M >rse s) stem i 

I in the United S • receiving instruments 

maintained ow c\o> ( \\ circuits, and the requisite 

trical impuls sent into the line by means of 

interruption- in the circuit obtained by the 

movements of a telegraphic key. Since the I 

ically on close! - of time, 

and batteries liable to p would be impra 

able ' 1 >ai iell's ; >n of a constant 

voltaic l overcame this o >n, and, together 

with the production of the electro-magnet, rendered the 
telegraph a posj commei i 

the benefit o\ those unacquainted with the nature 
of the effect produced in a vo at is 

called polarization, it may be stated that during 

i tltaic cell one oi tend to become 

red with a film of hydrogen or other similar* 
tro-j" substance, the effect of whi< ip an 

electro-motive force counter or contrary in direction to 
that produced 1 when in proper action. T 

-motive 

the efficient current produced by elL 

ell which polai maximum current 

only W moments after it is first set up and its 

circuit is closed In a very little while, the e 
polarization \ CU1 rent, so t : 

lectro receptive laced in the 

lor theij Ijustment as would any 



140 ELECTRICITY, 

telegraphic system impracticable from a commercial 
stand-point. 

Daniell's constant voltaic battery belongs to a class 
of instruments in which two fluid substances are em- 
ployed as electrolytes. The fluid that surrounds the 
negative plate, where the objectionable hydrogen col- 
lects, is chemically of such a nature as to be able to re- 
move the film of hydrogen by entering into chemical 
combination with it. 

In Daniell's constant cell this is done in a novel man- 
ner, the negative plate, the copper, being surrounded by 
a solution of copper sulphate so that the hydrogen that 
tends to be liberated at the surface, enters into combina- 
tion with the electro-negative radical of the copper sul- 
phate and deposits a film of copper on the surface of 
the plate. 

Daniell gives the following general description of his 
cell in a letter to Michael Faraday, which is quoted 
from the Philosophical Transactions for 1836, on page 
95, of Vol. I, of the "Annals of Electricity," published 
in London, in 1837. 

"In the construction of this battery, I have availed myself of 
the power of reducing the surface of the generating plates to a 
minimum, the effective surface of one of the amalgamated zinc 
rods being less than ten square inches, whilst the internal surface 
of the copper cylinder to which it is opposed is nearly 72 inches. 
My principal objects have been to remove out of the circuit the 
oxide of zinc, which has been proved to be so injurious to the 
action of the common battery, as fast as the solution is formed, 
and to absorb the hydrogen evolved upon the copper without the 
precipitation of any substance which might deteriorate the 
latter." 

"The first is completely effected by the suspension of the rod 
in the interior membranous cell, into which the fresh acidulated 



A HUNDRED YK.ars AGO and TO-DAY, HI 

The invention of the electro-magnet is the outgrowth 
of the life work of two remarkable inventors; namely, 

water is allowed slowly to drop from a funnel suspended over it, 
and the aperture of which is adjusted for the purpose ; whilst the 
heavier solution of the oxide is withdrawn from the bottom at an 
equal rate by the syphon tube. When both the exterior and in- 
terior cavities of the cell were charged with the same diluted acid, 
and connexion made between the zinc and copper by means of 
a fine platinum wire f}$th of an inch in diameter, I found that 
the wire became red hot, and that the wet membrane presented 
no obstruction to the passage of the current." 

"The second object is attained by charging the exterior space 
surrounding the membrane with a saturated solution of sulphate 
of copper instead of diluted acid ; upon completing the circuit the 
current passed freely through this solution ; no hydrogen made 
its appearance upon the conducting plate, but a beautiful pink 
coating of pure copper was precipitated upon it, and thus per- 
petually renewed its surface." 

"When the whole battery was properly arranged and charged 
in this manner, no evolution of gas took place from the generat- 
ing or conducting plates, either before or after the connexions 
were complete ; but when a voltameter was included in the cir- 
cuit, it- action was found to be very energetic. It was also much 
more steady and permanent than that of the ordinary battery ; 
but still there was a gradual, but very slow decline, which I traceO 
at length to the weakening of the saline solution by the precipL 
tation of the copper, and the consequent decline of its conduct- 
ing power." 

"To obviate this defect, I suspended some solid sulphate of 
copper in small muslin bags, which just dipped below the sur- 
face of the solution in the cylinders : which gradually dissolving as 
the precipitation proceeded, kept it in a state of saturation. This 
expedient fully answered the purpose, and I found the current 
perfectly steady for six hours together. This arrangement I 
have since improved by placing the salt on a perforated colander 
of copper fixed to the upper collar. 



142 ELECTRiCITY, 

of Oersted*, who in 1820 discovered the relation existing 
between the voltaic pile and electro-magnetism, and of 

* Prof. Oersteds discovery created great excitement 
in scientific circles. Davy thus communicated the dis- 
covery to the Royal Society of London in a letter read 
Nov. 16th, 1820, which I quote from page 217, of Vol. 
VI., of a publication called "The Collected Works of 
Sir Humphry Davy." 

"ON THE MAGNETIC PHENOMENA PRODUCED BY ELEC- 
TRICITY. IN A LETTER TO W. H. WOLLASTON, M.D., 
F. R. S. 

My Dear Sir, 

The similarity of the laws of electrical and magnetic attraction 
has often impressed philosophers ; and many years ago in the pro- 
gress of the discoveries made with the voltaic pile, some inquirers 
(particularly M. Ritter) attempted to establish the existence of 
an identity or intimate relation between these two powers ; but 
their views being generally obscure, or their experiments inac- 
curate, they were neglected ; the chemical and electrical phenom- 
ena exhibited by the wonderful combination of Volta, at that time 
almost entirely absorbed the attention of scientific men ; and the 
discovery of the fact of the true connection between electricity 
and magnetism, seems to have been reserved for M. Oersted, 
and for the present year. 

" This discovery, from its importance, and unexpected nature, 
cannot fail to awaken a strong interest in the scientific world; and 
it opens a new field of inquiry into which many experimenters 
will undoubtedly enter : and where there are so many objects of 
research obvious, it is scarcely possible that similar facts should 
not be observed by different persons. The progress of science 
is, however, always promoted by a speedy publication of experi- 
ments ; hence, though it is probable that the phenomena which I 
have observed may have been discovered before, or at the same 



A HUNDRED YEARS AGO AND TO DAY I43 

Amperet, who in the same year conducted that remark- 
able series ot investigations concerning the mutual 

attraetions and repulsions existing between circuits, 

time, in other parts of Europe, yet I shall not hesitate to communi- 
cate them to you. and through you to the Royal Society." 

u I found, in repeating the experiments of M. Oersted with a vol- 
taic apparatus of one hundred pairs of plates of four inches, that 
the south pole of a common magnetic needle (suspended in the 
usual way) placed under the communicating wire of platinum (the 
positive end of the apparatus being on the right hand) was strong- 
ly attracted by the wire, and remained in contact with it, so as en- 
tirely to alter the direction of the needle, and to overcome the 
magnetism of the earth. This I could only explain by supposing 
that the wire itself became magnetic during the passage of the 
electricity , through it, and direct experiments which I immediate- 
ly made proved that this was the case. I threw some iron filings 
on a paper, and brought them near the communicating wire, when 
immediately they were attracted by the wire, and adhered to it in 
considerable quantities, forming a mass round it ten or twelve 
times the thickness of the wire : on breaking the communication, 
they instantly fell off, proving that the magnetic effect depended 
entirely on the passage of the electricity through the wire. I tried 
the same experiment on different parts of the wire, which was 
seven or eight feet in length, and about the twentieth of an inch 
in diameter, and I found that the iron filings were everywhere at- 
tracted by it ; and making the communication with wires between 
different parts of the battery, I found that iron filings were at- 
tracted, and the magnetic needle affected in every part of the cir- 
cuit/' 

fThe labors of Ampere are thus referred to by Silli- 

man in his "Principles of Physics, or Natural Philoso- 
phy," nn page 605. 

"Immediately after the first announcement of (Ersted'a discov- 
ery oi aetie powers of a conjunctive wire, Ampere, one of 
the most renowned of the French Physicists (born 1755 — died 



144 ELECTRICITY, 

through which electrical currents are circulating, and 
propounded a theory for electro-magnetism, which led 
to the production of the electro- magnet. 

The electro-magnetic telegraph belonged to the third 
type of inventions ; namely, of ripe inventions, and, 
the electro-magnet and the Daniell's battery having 

1836), commenced a series of experiments (September, 1820) to 
determine the laws concerned in these curious phenomena. Of 
three principal hypothesis which he framed to this end, he finally 
accepted and demonstrated the following ; viz. 

" A magnet is composed of independent elements or molecules, which 
act as if a closed electric circuit existed within each of them : in other 
words, each of these magnetic molecules may be replaced by a conjunc- 
tive wire bent on itself in which a constant current of electricity is 
maintained, as from a Voltaic circuit. 

" This hypothesis he maintained by singularly ingenious experi- 
ments, many of which were the direct suggestion of the hypothe- 
sis itself, and he brought all, by his power of mathematical analy- 
sis, into exact conformity with his theory. This theory recog- 
nises only such forces as are common to mechanical physics, and 
often called 'push and pull ' forces. These forces are mutual, 
and belong to all electric currents. In permanent magnets, the 
minute circular and parallel currents, pertaining, by this theory, 
to each magnetic molecule, all act at right angles to the magnet- 
ic axis or line of force. Hence, as in QErsted's experiment, the 
magnetic needle strives to place itself at right angles to the path 
of the current on the conjunctive wire, it follows, that currents in 
the magnet seek a parallelism to that in the conjunctive wire. 
Granting this to be true, it follows, as a corollary from the premi- 
ses, — 

" 1st. That two free conducting wires must attract or repel each 
other, according to the direction of the currents in them. 

" 2d. That a conjunctive wire may be made in all respects to simu- 
late a magnet" 



A HUNDRED YEARS AGO AND TO-DAY. I45 

been produced, we quite naturally find 1837 a memo- 
rable year in the history of telegraphy. ^V number of 
claimants appear for the honor of its first conception; 
among these are Morse* in America, Steinheil in Munich, 
and Wheatstone and Cooke in England. 

f *Like other great inventions the telegraph was not 
created in a single day. For many years prior to the com- 
pletion of the invention Morse pondered and contrived. 
He asserts that the germs of the invention were sown 
on board the packet ship Sully, while on a voyage from 
Havre to New York City. The vessel sailed from 
Havre, October 1st, 1832. During the voyage Morse 
made numerous sketches of the apparatus. 

Morse gives the following account of his invention 
of the electro-magnetic telegraph, on page 48, of a 
publication called "The Telegraph in America. Its 
Founders, Promoters, and Noted Men, ' by James I). 
Reid, New York, Derby Brothers, 1879. 

"Before the end of the voyage on the Sully the invention had 
the following attributes. My aim at the outset was simplicity of 
means, as well as results. Hence, I devised a single circuit of con- 
dors from some generator of electricity. I planned a system of 
signs, consisting of dots or points, and spaces, to represent nu- 
merals, and two modes of causing the electricity to mark or im- 
print these signs upon a strip or )-\i>h<>n of paper. One was by 
chemical decomposition of a salt which should discolor the paper ; 
the other was by the mechanical action of the electro-magnet^ oper- 
ating upon the paper by a Irrrr. charged at one extremity with a 
pen or pencil. I conceived the plan of moving the paper ribbon 
at s* regular rate, by means of clock-work machinery to receive the 

sigi ■•■ processes, as well as the mathematically calculated 

signs, devised for and adapted to recording, were sketched in my 
sketch-book. I also drew in my sketch book modes of interring 



I46 ELECTRICITY, 

The telegraphic apparatus of the two last (Steinheil 
and Wheat^tone) says Prof. J. D. Forbes in the 8th 
Edition of the "Ency. Brit. America/' resembles in 
principle Oersted's and Gauss' : that of the first (Morse) 
is entirely original, and consists in making a ribbon 
of paper move by clock-work whilst interrupted marks 
are impressed upon it by a pen, etc. * * * * > 

the conductors in tubes in the earth, and, soon after landing, 
planned and drew out the method upon posts. This was the gen- 
eral condition of the invention (with the exception of the plan 
upon posts) when I arrived in New York, on the 15th of Novem- 
ber, 1832." 

" In reflecting on the operations of electricity as a proposed 
agent in telegraphy, I was aware that its presence in a conductor 
of moderate length could be indicated in several ways. The phy- 
sical effects in a shock ; the visible spark ; visible bubbles during 
decomposition, and marks left from decomposition ; its magnet- 
ic effects upon soft iron and steel ; and its calorific effects, — these 
were all well-known phenomena. Could any of these be made 
available for recording, and at a great distance ? If so, which 
of them seemed to promise the surest result of a permanent record ? 
Static electricity was quickly dismissed as too uncontrollable, and 
I directed my attention exclusively to the phenomena of dynam- 
ic electricity. The decomposition of a salt having a metallic ba- 
sis would leave a mark upon paper or cloth. If a strip of paper 
or cloth were moistened with the salt, and were then simply put 
in contact with a conductor charged with electricity, would there 
be any effect upon the paper ? A magnetic effect is produced ex- 
terior to the charged conductor. Is there any salt or substance so 
sensitive as to be affected either by decomposition, or in any 
other way, by this magnetic influence, by simple contact with an 
electrically charged wire ? It was doubtful, but worth an experi- 
ment. " 

Again on page 63, of the same book, he says, 



A HUNDRED YEARS AGO AND TO-DAY. 147 

"The telegraphs of Morse have the inestimable ad- 
vantage, that they preserve a permanent record of the 
dispatch they convey." 

I need not describe Morse's method to you. It con- 
. as you know, in the employment of an electro- 
magnet to the armature of which is attached a stylus or 
point that records on a fillet of paper drawn underneath 
it, a series of dots and dashes corresponding to the 
letters of the alphabet. 



"Between the date, 1835, of the completion of the first instru- 
ment and 1837, the date of its more public exhibition, there was 
a very important addition to it, which I had already devised and 
provided Against a foreshadowed exigency, to meet it if it should 
occur when the conductors were extended, not to a few hundred 
feet in length in a room, but to stations many miles distant. I 
was not ignorant of the possibility that the electro-magnet might 
be so enfeebled, when charged from a great distance, as to be in- 
operative for direct printing. This possibility was a subject of 
much thought and anxiety long previous to the year 1830, long 
previous to my acquaintance or consultations with my friend 
Prof. Gale on the subject, but I had then already conceived and 
drawn a plan for obviating it. The plan, however, was so simple 
that it scarcely needed a drawing to illustrate it ; a few words suf- 
ficed to make it comprehended. If the magnet, say at twenty 
- distant, became so enfeebled as to be enabled to print di- 
rectly, it yet might have power sufficient to close and open anoth- 
er circuit of twenty miles farther, and so on until it reached the 
required station. This plan was often spoken of to friends pre- 
vious to the year 1836, but early m January. 1836, after showing 
the original insi rnment in operal i<>n to my friend and ooll< 

Prof. Gale, I imparted to him tins plan of a relay battery and 

>lve his doubt- regarding the practicability of my 
-• power sufficient to write at a distai 



I48 ELECTRICITY, 

The first submarine cable was first successfully laid 
between Dover, England, and Cape Griz Nez, France, 
in 1 85 1. The first Atlantic cable was laid between 
Newfoundland and Ireland by Cyrus W. Field, in 1858.* 

*The following description given of the first an- 
nouncement made by Cyrus W. Field, of the successful 
laying of the first Atlantic cable, is taken from page 
279, of "The Laying of the Cable, or the Ocean Tele- 
graph/' by John Mullaly, New York : D. Appleton & Co., 
1858. 

MR. FIELD MAKES THE FIRST ANNOUNCEMENT TO 
THE NEW WORLD THAT THE CABLE IS LAID. 
"About eight o'clock on the evening of the 4th instant, while 
the Niagara was proceeding up Trinity Bay, and some seventeen 
or eighteen miles distant from the landing place, Mr. Field left 
the ship for the purpose of visiting the telegraph station, and if 
possible, of sending a despatch to the United States announcing 
the success of the enterprise. As the boat of the Porcupine was 
along-side, it was cheerfully placed at his disposal by Captain 
Otter, who had now undertaken to pilot the Niagara. Mr. Field 
immediately set out, and as the Gorgon was on her way to the 
Bay of Bull's Arm, at the head of which the cable was to be landed, 
he went on board that vessel, and his boat was taken in tow. 
Here he was warmly received by Captain Dayman and his officers, 
who were in the full enjoyment of success. It was near two 
o'clock in the morning before he arrived at the beach, and as it 
was quite dark, he had considerable difficulty in finding the path 
that led up to the station. There was no house in sight, and the 
whole scene was as dreary and as desolate as a wilderness at night 
could be. A silence as of the grave reigned over everything be- 
fore him ; while behind, at the distance of a mile, he could see the 
huge hull of the Niagara looming up indistinctly through the 
gloom of night, and the light of her lamps on her deck making the 
darkness still darker and blacker by the contrast. He entered the 



A HUNDRED YEARS AGO AND TO-DAY. 1 49 

Contrasting the telegraphic apparatus which has been 
devised since that of Morse in 1837, and that in use at 
the present day, we find an almost continuous record 
of marked progress. 

narrow road, and after a journey of what appeared to be twenty miles 
came in sight of the station, which stands about half a mile from 
the beach. There was, however, no sign of life there, and the 
house, in its stillness, seemed strangely in unison with everything 
around. It had a deserted appearance, as if it had long since ceased to 
be the habitation of man. In vain he looked for a door in the 
front : there was no entrance there ; he looked up at the windows in 
the hope, perhaps, of being able to enter by that way, but the win- 
dows of the lower story were beyond his reach, and the house hav- 
ing been partly built on piles gave it the appearance of being 
raised on stilts. A detour of the establishment, however, led to 
the discovery of a door in the side, and through this he finally suc- 
ceeded in effecting an entrance. The noise he made in getting in, 
it was natural to expect, would arouse the inmates, but there 
seemed to be either 110 inmates to arouse, or those inmates were 
not easily disturbed. He stopped for a moment to listen, and as 
he listened he heard the breathing of sleepers in an apartment near 
him. The door was immediately thrown open, and in a few seconds 
the sleepers were awake, wide awake, and opening their eyes 
wider and wider as the wonderful news fell upon their astonished 
and delighted ears. They could hardly believe the evidence of 
their E -.d were bewildered at what they heard. The cable 

laid! when but a few short weeks before they had received the 
tei and defeat, and they had looked only to the far 
t future for the accomplishment of the great work. The 
cable laid, and they unconscious of it — they who had waited and 
watched so many weary days and weeks for the ships they had 
begun to I ronld never come. What ! and they were now 

in the bay— th within a mile of them ! can they 

be dreaming F Dreami- what they have heard is true, all 

and there is the living witness before them." 

• u want f " was the exclamation of the first who 



i 5 o 



ELECTRICITY, 



From 1837 to the present day, the world has witnessed 
the wonderful inventions of duplex telegraphy, includ- 
ing both diplex, which consists in the simultaneous 



was awakened, as he endeavored to rub the sleep out of his eyes." 
" I want you to get up," said Mr. Field," and help us take the 
cable ashore." 

" To take the cable ashore ! " re-echoed the others, who were now 
just awaking, and who heard the words with a dim, dreamy idea 
of their meaning — " To take the cable ashore ? " 
" Yes," said Mr. Field, "and we want you at once." 
They were now thoroughly aroused, and directing Mr. Field to 
the bedrooms of the other sleepers — for there were four or five 
others in the house — they prepared themselves with all haste to 
assist in landing the cable. But the other inmates were already 
awake, and when Mr. Field made his appearance on the corridor 
which divides the sleeping apartments on each side of the house, 
he found them awaiting him in the lightest description of sum- 
mer clothing. As they had neither pants, vests, coats, shoes nor 
stockings on, the curious will have no difficulty in discovering in what 
they were dressed. They were as amazed at seeing Mr. Field as if 
he were an apparition ; and when they recovered themselves suf- 
ficiently to ask the meaning of such a strange visitation, they 
were thrown into another state of wonderment by what he re- 
lated. When they learned all, they dressed, and prepared them- 
selves for the work before them. Mr. Field found that the tele- 
graph office would not be open till nine o'clock that morning, and 
that the operator of the New York, Newfoundland and London 
Telegraph was absent at the time. He also ascertained that the 
nearest station at which he could find an operator was fifteen 
miles distant, and that the only way of getting there was on foot. 
Now, fifteen miles in Newfoundland is about equal to twice that dis- 
tance in a civilized country, and is a tolerably long walk ; but it was 
something to be the bearer of such news to a whole continent, and 
so two of the young men willingly volunteered for the journey 
bearing with them, for transmission to New York and the whole 
United States, the following despatch, which contained the first 



A HUNDRED TEARS AGO AND TO-DAY. 151 

transmission of messages over the same wire in the 
same direction, and the contraplex, which consists of such 

simultaneous transmission oi mes In opposite 

announcement of the successful accomplishment of the work, and 
the historical importance of which will justify its republication 
here : 

u United States Steam Fbigate Niagaba, 

Tkinity Bat, Newfoundland, August 5, 1858. 
To the Associated Pecs*. New York : 

The Atlantic Telegraph fleet sailed from Queenstown, Ireland, 
Saturday, July 17. met in mid-ocean. Wednesday, the 28th, made 
the splice at one P. M.. Thursday," the 29th, arid separated. The 
Agamemnon and Valorous bound to Valentia. Ireland, the Niag- 
ara and Gorgon for this place, where they arrived yesterday, and 
this morning the end of the cable will be landed. It is 1,696 nau- 
tical, or 1,960 statute miles from the telegraph house at the head 
of Valentia harbor to the telegraph house at the Bay of Bull's 
Arm, Trinity Bay. and for more than two-thirds of this distance 
the water is over two miles in depth." 

"The cable has been put out from the Agamemnon at about 
the same speed as from the Niagara." 

" The electrical signals sent and received through the whole ca- 
ble are perfect." 

L6 machinery for paying <>ut the cable worked in the most 
satisfactory manner, and it was no1 stopped for a single moment 
from the time the splice was made till we arrived her* 

M Captain Hudson, Messrs. Everett and Woodhouse, the • 
i, the electricians, officers of the ships, and. in fact, every man 
on board the telegraph fleet, have exerted themselves to the utmost 
to make the expedition successful, and by the blessing of Divine 
vidence it has succeeded." 

ter the end of the cable is landed and connected with the 
land line of telegraph, and the Niagara has discharged some ear- 
go bel .i'h Company, she will go to St. Johns 
• al and water, and then proceed at oner to New York." 

"CYBUS W, FIELD. 1 



152 



ELECTRICITY, 



directions. It has witnessed the invention of quad- 
ruplex telegraphy, or of the simultaneous transmission 
over the same wire of four separate and distinct mes- 
sages, two in one direction, and the remaining two in 
the opposite direction ; of multiple telegraphy, in which, 
as in the harmonic system of Gray, a number of mes- 
sages, greater than four, are simultaneously transmitted 
over the same wire ; or, as in the synchronous multiplex 
system of Delaney, as many as 72 separate and distinct 
messages have been successfully transmitted over the 
same wire, either all in one direction, or a number in 
one direction, and the remainder in the opposite di- 
rection. 

It was unquestionably the classic investigations of 
Faraday, described along with other researches in his 
1 ' Experimental Researches " * in the domain of magneto- 
electric induction, that gave to the world that most 



^Faraday's magnificent experimental researches in elec- 
tricity are published in three volumes, and 29 series, 
with addenda in "Faraday's Experimental Researches 
in Electricity " Vol. I and II, London : Bernard Quar- 
itch, 1839 and 1844 and Vol. ^ By Richard Taylor and 
William Francis, London: 1855. 

In the preface to Vol. 1, Faraday speaks thus on page 
iii : 

" I have been induced by various circumstances to collect in 
One Volume the Fourteen Series of Experimental Researches in 
Electricity, which have appeared in the Philosophical Transac- 
tions during the last seven years ; the chief reason has been th§ 






A HUNDRED YEARS AGO AND TO-DAY. 1 53 

wonderful and efficient electric source the modern dy- 
namo-electric machine. The successful production of 
the modern type of dynamo machine probably found 
its first exponent in the completed Gramme machine. 
It was, probably mainly, this machine that i^ave that 
wonderful impetus to electric science which, beginning 
about 1874-75, has continued to the present day, and 
furnishes one of the best examples of remarkable prog- 
ress along a particular line of science that the world 
lias ever seen. To attempt to trace the history of the 
dynamo-electric machine would more than fully occupy 
the time generally assigned to a single lecture. Suffice 
it to say that the first machine of this type was invented 
by Faraday, and was described in a communication to 
the Royal Society read during the latter part of 183 1. 

Faraday modestly describes this remarkable invention 
merely as "A New Electrical Machine." Faraday's dy- 
namo consisted essentially of a disk of copper about 12 
inches in diameter, so mounted on an axis as to be ca- 
pable of rotation between the opposite poles of a pow- 
erful permanent magnet. Two collecting brushes, rest- 
ctively on the axis and on the circumference of 
the wheel, sufficed to carry off the current generated by 

to supply at a moderate price the whole of these papers, 
with an Index, to those who may desire; to have them." 

adere of the volume will. I hope, do me the justice to 

that it was not written as a whole % but in parts ; the 

earlier portions rarely having any known relation at the time to 

khoee which might follow. If I had rewritten the work, I, per- 



154 electricity, 

means of the potential difference produced as the rotat- 
ing disk cuts through the lines of magnetic force of the 
permanent magnet. In this way electric currents were 
produced for the first time from permanent magnets. 

Shortly afterwards Dal Negro and Pixii constructed 
more powerful machines on similar principles, and 
from that time up to the present, numerous inventors 
have appeared who have produced dynamo-electric 
machines of greater or less merit ; among these I will 
merely mention the names of Ritchie, Saxton, Clarke, 

haps, might have considerably varied the form, but should not 
have altered much of the real matter : it would not, however, then 
have been considered a faithful reprint or statement of the course 
and results of the whole investigation, which only I desired to 
supply." 

" I may be allowed to express my great satisfaction at finding, 
that the different parts, written at intervals during seven years, 
harmonize so well as they do. There would have been nothing 
particular in this, if the parts had related only to matters well as- 
certained before any of them were written : — but as each pro- 
fesses to contain something of original discovery, or of correc- 
tion of received views, it does not surprise even my partiality, 
that they should have the degree of consistency and apparent gen- 
eral accuracy which they seem to me to present." 

There are probably few books in the extended litera- 
ture of electricity, if indeed there be any, which will so 
well reward the student as a careful reading, and re- 
reading of this masterly production, and I earnestly rec- 
ommend the volumes to all who have not yet read 
them, who wish to become thoroughly grounded in elec- 
tric science. 



A HUNDRED YEARS AGO AND TO-DAY. 1 55 

Jacobi, Sturgeon, Wheatstone, Brett, Hiorth, Page, 
Holmes, Wilde, and finally, the well-known inventors 
of our own days. 

Faraday built better than he knew. Could he see 
the many forms of dynamos, which are now, in all parts 
of the world, converting mechanical energy into elec- 
trical energy with wonderful efficiency, he would ap- 
preciate the almost immeasurable value of the gift he 
freely gave to the world. 

The cheap and reliable production of electricity on an 
extended scale, which was thus for the first time ren- 
dered possible by the successful invention of the dyna- 
mo, rendered many applications feasible on a commer- 
cial scale that had hitherto been limited to mere labora- 
tory experiments. Prominent among these may be 
mentioned the use of the electric light for the purpose of 
artificial illumination on a commercial scale. The prob- 
lem of successful arc lighting first was solved, and at 
present, in widely separated parts of the world, the day 
is extended far into the night by means of arc lights. 
Hundreds of thousands of arc lights, consuming miles 
and miles of carbon rods every night, show the wonder- 
ful development of this remarkable industrial outgrowth 
of Faraday's ^reat discovery. 

Then came the - : ul solution of the divisibility of 

the electric light by the invention of the incandescent 
lamp. It would be interesting, if time permitted, to give 
a brief account of the labors of the numerous able in- 



I56 ELECTRICITY, 

ventors whose life-work was required to finally produce 
the modern incandescent electric lamp. I would men- 
tion many distinguished names, but you are, however, 
well acquainted with them. I would tell you of the 
patient search for a suitable material for the incandes- 
cing filaments ; of the various processes that were tried 
and rejected for preserving the filament from destruc- 
tion ; of the production of the enclosing all-glass lamp 
chamber ; of the process for shaping the fibrous 
carbonizable material prior to its carbonization : of 
the care required in subjecting it to the carbonizing 
process ; of the means necessary for ensuring uniformi- 
ty in its light-producing power throughout all parts of its 
length ; of the invention of the occluded-gas process, 
whereby a vacuum was permanently maintained in the 
lamp chamber, of the exhaustion and final sealing of the 
lamp chamber ; and of the many other points, which ap- 
pear insignificant in themselves, but which are, in reali- 
ty, of vital importance to the production of a successful 
commercial incandescent electric lamp of long life and 
high efficiency. Suffice it to say that the incandescent 
electric lamp, like the arc light, is to-day a commercial 
success, and its continuance is assured, at least until re- 
placed by something far better. 

The invention of the modern dynamo electric machine 
rendered the extended commercial application possible 
of another invention made by numerous parties many 
years before. I allude to the invention of the electric 



A HUNDRED YEARS AGO AND TO-DAY. 



J 57 



motor, which, during the past few years has been suc- 
cessfully developed and put into actual use to an extent 
that appears almost incredible. Indeed, already, the va- 
rious commercial applications of electricity as a motive 
power are such that it is doubtful if they do not already 
rival in extent the applications of electricity for the pro- 
duction of light.* 



*To trace the early history of the electric motor would 
require a volume in itself, and that too, one of no mean 
dimensions. I shall, therefore, content myself in this 
connection, by the following- description of the Jacobi 
and Page motors taken from pages 8 and 9 (3rd edition) 
of " The Electric Motor and its Applications," by Mar- 
tin and W etzler. New York : The W. J. Johnston Com- 
pany, LYd, 1892. 

" Thanks to the substantial aid of the Emperor Nicholas of Rus- 
sia, who contributed a sum of $12,000 to the work, Professor Ja- 
cobi. the discoverer of electro-plating, was enabled to prove in 
1838, at St. Petersburg, on the Neva, that his electromagnetic 
motor of 1834. as improved, could replace the oarsmen in a boat 




J.v obi Motor. 
carrying a dozen passengers. Above is a perspective of the Ja- 
cobi motor of 1834:, which was composed of two sets of electro- 
magnets. One sot was fastene l to the square frame 7\ disposed 
in a circle and with the pole* projecting parallel with the axis. 
The other set 8 was similarly fastened to the disc .1 attached to 



158 ELECTRICITY, 

The first invention of the electric motor was very 
markedly the case of an unripe invention. Its success- 
ful commercial application necessarily failed for the want 
of some cheap means for producing the electric current 
required to drive it. Prior to the invention of the dyna- 
mo, the voltaic battery was the only available source 
for the production of large currents of electricity ; but 
even the most efficient electric motor of the present day, 

the shaft and revolving with it. Each set comprised four mag- 
nets, and there were consequently eight magnetic poles. The 
current from a powerful battery passed through the commutator 
C to the coils of the electro-magnets, and as the magnets attract- 
ed each other the disc rotated. By means of the commutator on 
the shaft, the current was reversed eight times during each revo- 
lution, just as the poles of two sets of magnets arrived opposite 
each other. Attraction ceasing, repulsion took place, and the mo- 
tion was thus accelerated. As the poles were alternately of dif- 
ferent polarity, the reversals had ths effect of causing attraction 
between each pole of one set and the next pole of the other. In 
his historic experiments of 1838, Jacobi used a modified form of 
this motor, so as to obtain greater power. In the new form, two 
sets of electro-magnets were attached to stationary vertical 
frames, one on each side of a rotating disc or star. Each set was 
composed of twelve electro-magnets. The electro-magnets on the 
rotating star were made in the form of bars passing entirely 
through the star. The axis carried a commutator formed of four 
wheels, regulating the direction of the current with the result that 
when the straight bar magnets were between two consecutive poles 
of the horse-shoe magnets on the frames, they were always at- 
tracted towards the one and repelled from the other. The rever- 
sal of the current took the place when the rotating poles were ex- 
actly opposite the fixed ones. 

The following description of Page's motor is taken 
from page 19 of the same book : 

"The most celebrated early motor next to that of Jacobi was 



A HUNDRED YEARS AGO AND TO-DAY. 1 59 

driven by electricity so generated, could never hope to 
compete with the steam engine ; for, in order to produce 
currents by the voltaic pile it is necessary to burn zinc 
in some costly acid. Then, too, the number of heat 
units produced by the combustion ol a pound of zinc is 
much smaller tfc^n the number produced by the combus- 
tion of a pound of carbon, the proportion being in about 
the ratio of 1,300 to 8,000. Until, therefore, zinc be- 
came cheaper than coal in a corresponding ratio, and 
sulphuric acid cheaper than ordinary air, the commer- 
cial use of the electric motor as driven by such means 
would of course be impracticable. 

The early history of invention in the line of electric 
motors include a number of well known names, the 
most prominent of which, as I now recall them, are Ja- 

undoubtedly that of Professor C. G. Page of the Smithsonian In- 
stitute. This depended on a different principle from that of the 
others. When the end of a bar of iron was held near a hollow 
electro-magnetic coil or solenoid, the iron bar was attracted into 
the coil by a kind of sucking action until the bar had passed half 
way through the coil, after which no further motion took place. 
Professor Page constructed an electric engine on this principle 
about 1850. The solenoid was placed vertically, like the cylinder 
of an upright engine. A rod of iron, by way of armature, was 
fastened to a piston-rod connected to the crank of a shaft car- 
rying a fly-wheel. The core moved downward by its weight, un 
til its upper end was just leaving the solenoid, and thus one 
movement of the piston was accomplished. On passing the cur- 
rent the core or piston was attracted upward, and thus the sec- 
ond movement was completed. A commutating device was at- 
tached to the shaft which automatically admitted the current into 
the coil and cut it off at the right moment.'' 



l6o ELECTRICITY, 

cobi, Page, Ritchie, Wilde, Dal Negro, and, coming down 
to the present day, the well known inventors whose suc- 
cessful electric motors are now occupying so important 
a field in various lines of work. 

There is a circumstance connected with the operation 
of an electric motor to which I wish to call your atten- 
tion, for it appears to show unquestionably that the 
electric motor is destined at an early date to occupy an 
even more extended field of usefulness than it does at 
present. This circumstance, briefly, is to be found in 
the fact that a properly constructed electric motor auto- 
matically regulates the amount of current that passes 
through its circuit in proportion to the load that is placed 
therein ; or, in other words, to the work that the motor 
is given to perform. 

The self-regulating power of an electric motor is to 
be traced to the fact that, during its rotation when en- 
ergized by the driving current, an electro-motive force is 
generated in its coils counter, or opposite in direction to, 
that which is applied to its terminals for the purpose of 
sending a driving current through it. This electro-mo- 
tive force is called the counter electro-motive force of the 
motor. It tends to produce a current contrary in direc- 
tion to that of the current which is passing through its 
coils and so decreases the amount of such current. 

The counter electro-motive force produced by an elec- 
tric motor during its rotation increases with the speed 
of rotation. Whenever, therefore, during the rotation 



A HUNDRED YEARS AGO AND TO-DAY. l6l 

of the motor, the amount of work which the machine 
has to perform is decreased and the motor tends to run 
at a higher speed, the counter electro-motive force is in- 
creased, and, consequently, the amount of current that 
is permitted to pass through the motor is correspondingly 
decreased. When, however, an increased load is put 
on the motor, and the machine thereby slows up, on 
this decrease in the rapidity of its rotation, the counter 
electro-motive force is decreased and consequently the 
amount of current which passes through the motor is 
correspondingly increased. In this way the current 
which drives the motor is automatically regulated with 
great nicety. 

There is another reason why the future of the electric 
motor appears to be so bright. This is found in the high 
efficiency of the modern electric motor. Electric motors 
of an efficiency as high or even higher than 90 and 95 
per cent, can be produced. Contrast this with the effi- 
ciency of the modern triple expansion steam engine, 
where an efficiency of 17 per cent, would be regarded as 
higher than, perhaps, the actual facts warrant. It 
would seem far from improbable, therefore, that the 
steam engine will, before long, become a thing of the 
and this will come as soon as some successful 
method is invented for producing electricity more 
ply than it can be produced by the intervention 
of a steam engine. 

Ind r en at the present tin. 



1 62 ELECTRICITY, 

motor power is already successfully competing with 
steam in a number of cases. Examples of such suc- 
cessful competition are seen in cases where a reliable 
water power exists ; for, in such cases, by the erection of 
a suitable water-wheel, the energy of the stream can be 
converted into electrical energy and this can be trans- 
mitted by wires or conductors over distances of many 
miles. A single prime motor, in the shape of a water- 
wheel can, in this manner, drive secondary motors at 
localities hundreds of miles distant. 

Contrast the old method of driving secondary motors 
from a prime motor, by means of belting or gearing, with 
more recent means of transmitting electrical power 
through conductors, for distances of hundreds of miles 
and upwards, and you will see how great a rival steam 
power may soon expect to find in electric power. Look, 
for example, at that great problem of to-day, rapid 
transit by means of electricity, and see how efficient 
and satisfactory such systems for the propulsion of 
street railway cars have been found in almost every lo- 
cality where they have been introduced. 

But, in the meantime, let us not forget that most 
wonderful of modern discoveries which was made in 
1 86 1, by Philip Reis, of Germany. I know that it is 
not an entirely recognized fact that the telephone was 
invented by this gentleman ; but, as I read the rec- 
ords of the past, I find, as I believe a majority of 
scientific men of the present day find, that Philip Reis 



A HUNDRED YEARS AGO AND TO-DAY. 1 63 

did in reality invent this remarkable instrument. 
Whether this invention failed of commercial success, 
because it was immature or unripe, I will not now take the 
time to discuss, although I should he pleased to do so. 
Let it suffice to say that it was not until 1S76 that Bell, 
of America, produced the first articulating telephone 
which was introduced into actual use on an extended 
commercial scale. 

Like all other great inventions, the telephone has not 
been the product of a single mind. The inventions of 
many able minds were required to bring it to its 
present state of efficiency ; and there can be no reason- 
able doubt that, were the competition greater, the in- 
strument would be improved very far beyond its 
present achievements. 

L m >king at the telephone from a strictly scientific stand- 
point, it affords an admirable instance of the combined 
application of the three great inventions which we have 
just been discussing ; namely, the dynamo-electric 
machine, the electric motor, and the long distance trans- 

— ion of electric power. 

A speaker talking into the receiving instrument of a 
:ieto-electric telephone, at one end of a line wire or 
conductor, plays the part of a prime mover and furnishes, 
through the sound waves he originates, the mechanical 
energy required to move an iron diaphragm towards or 
from a magnet pole. The energy so supplied, like the 
energy Supplied by a steam engine to a dynamo-electric 



1 64 



ELECTRICITY, 



machine, produces electric currents ; for a magneto- 
electric telephone, when used as a transmitter is, in 
reality, a dynamo-electric machine driven by the voice 
of the speaker. The electric currents so produced are 
transmitted over a line wire or conductor, and, passing 
through .the coils of a receiving instrument in the form of 
an electric motor, reproduces in its diaphragm motions 
exactly corresponding to those produced by the speaker's 
voice in the transmitting instrument. Consequently a 
person listening at the receiving instrument will hear 
all that is spoken into the transmitting instrument. 

An outgrowth of the telephone appeared in the phono- 
graph, the invention of Edison. In this instrument the 
speaker's voice, directed against an elastic diaphragm, 
causes a stylus or pen attached thereto to produce in- 
dentations on the surface of a sheet of tin-foil or other 
suitable surface, that is mechanically moved under the 
diaphragm. In order to reproduce this speech at any 
subsequent time a corresponding stylus, attached to a 
diaphragm, is given a to-and-fro motion by causing 
such stylus or point to be mechanically moved over the 
indented tin-foil surface. As this stylus climbs the hills 
and is pushed into the hollows of the record surface, it 
produces in the diaphragm of the receiving instrument 
motions precisely similar to those by which its impres- 
sions were made, and, consequently, causes such re- 
ceiving diaphragm to reproduce the sounds uttered into 
the transmitting diaphragm. 



HUNDRED YEARS AGO AND TO-DAY, 1 65 

An invention somewhat similar to the telephone is 
found in the instrument called the telephote, by means 
of which communication is carried on along rays of 
light instead conducting wires. But time 

press - ind I have yet to call your attention to many 
other remarkable inventions, ot which I must, perforce, 
make but brief mention. 

In 1821, Siebeck,* of Berlin, showed that electrical 

currents could be produced by the contact of dissimilar 

me1 - soldered together so as to form 

circuits, provided their junctions were maintained at 

rtain difference of temperature. 

♦Sic - first experiment was made by using an 

electric circuit ot a bar of bismuth and a bar of copper so 
soldered together as to form a hollow ie. When 

one of the junctions of such a circuit was heated a current 
of electricity was produced, the passage of which 
through the circuit was shown by the deflection of a 
magnetic needle supported inside the rectangle, so as to 
be free to move in a horizontal direction. 

Sit' at the direction of the electric cur- 

rent so pr< in the junction that was 

heated. I in one direction when one 

jui. I in the op- 

1 when the other junction w <i. 

In • ie man;. current 

either junction was in th >n to that 

produced by heating that juncti 

Siebeck pr :he name of them trie cur- 

rents for the electricity thus produced, and this name is 



i66 



ELECTRICITY, 



Although the discovery of thermo-electricity by bie- 
beck has never amounted to much commercially, yet 
this would reasonably appear to be in the near future, 
one of the directions along which the most marked 
progress is to be made in electric science. 

In 1827, Dr. G. S. Ohm,* of Berlin, made a remarkable 
mathematical discovery, which is known in science as 



now generally accepted ; he called the combination of 
the two metals or other substances necessary to produce 
the phenomena a thermo-electric couple, and the sepa- 
rate metals or substances, the thermo-electric elements. 
He found that very many metallic and non-metallic 
substances were capable of forming thermo-electric 
couples, and formed a thermo-electric series, arranged 
according to the order of their thermo-electric powers. 

* Dr. Ohm published the results of his classic investi- 
gations in 1827, in a paper entitled "Die Galvanische 
Kette mathematisch bearbeitet von Dr. G. S. Ohm." 
" The Galvanic Current Mathematically Investigated by 
Dr. G S. Ohm." 

Probably no purely mathematical papers in the do- 
main of electric science appeared during the time of 
Ohm, or, indeed, probably in any time, that contained 
so valuable a generalization as the fundamental principle 
concerning the laws of the electric circuit that Dr. Ohm 
thus first enunciated. Dr. Ohm's article is quite lengthy 
and forms a small volume in itself. I append a few 
quotations taken from a translation by Mr. William 
Francis in 1827, as published on page 416, of Vol. 2, of 
a publication entitled "Scientific Memoirs Selected from 



A HUNDRED TSARS AGO AND TO-DAY. 167 

Ohm's law. This law is generally expressed as follows : 
The current strength in any circuit is equal to the 
electro- motive force divided by the resistance; or, as you 

the Transactions oi Foreign Academies of Science and 

Learned Societies" by Richard Taylor, London: 1841. 

u The force of the current in << galvanic circuit is directly as (he 

sum of all the tensions^ and inversely as the entire red vent length of 

the circuit, bearing in mind that at present by red need Length is 
understood the sum of all the quotients obtained by dividing the 
actual lengths corresponding to the homogeneous parts by the 
product of the corresponding conductibilit it's and section-." 

u From the equation determining the force of the current in a 
galvanic circuit in conjunction with the one previously found, by 
which the electric force at each place of the circuit is given, may 
be deduced with ease and certainty all the phenomena belonging 
to the galvanic circuit. The former I had already some time ago 
derived from manifoldly varied experiments with an apparatus 
which allows of an accuracy and certainty of measurement not 
suspected in this department ; the latter expresses all the obser- 
vations pertaining to it, which already exist in great number, 
with the greatest fidelity, which also continues where the equa- 
tion leads to results no longer comprised in the circle of previous- 
ly published experiments. Both proceed uninterruptedly hand 
in hand with nature, as I now hope to demonstrate by a short 
statement of their consequences : at the same time I shall consi I- 
er it necessary to observe, thai both equations refer to all possi 
ble galvanic circuits whose state is permanent, consequently they 
comprise the voltaic combination as a particular case, so that the 
theory of the pile need- no separate comment." 

The reduced length referred to in the above quotation 
the equivalent of the resistance of the circuit and is 
based on the character and dimensions of the substance 
forming the circuit. 

And on page 422 of the same publication. 

" All the • opic actions of a galvanic circuit ot the kind. 



1 68 ELECTRICITY, 

will find it mathematically in almost any electrical book 

E 
you may chance to open, C = — . 

R 
This law is only true for continuous currents, as indeed 
Ohm suggests, another law being necessary to express 
similar relations in the case of alternating currents. 

described at the outset, have been above stated ; I therefore pass 
at present to the consideration of the current originating in the 
circuit, the nature of which, as explained above, is expressed at 
every place of the circuit by the equation 

A 

L " 
Both the form of this equation, as well as the mode by which we 
arrive at it, show directly that the magnitude of the current in such 
a galvanic circuit remains the same at all places of the circuit, and 
is solely dependent on the mode of separation of the electricity, so 
that it does not vary, even though the electric force at any place of the 
circuit be changed by abductivs contact, or in any other way. This 
equality of the current at all places of the circuit has been proved 
by the experiments of Becquerel, and its independency of the elec- 
tric force at any determinate place of the circuit by those of G. 
Bischof. An abduction or adduction does not alter the current of 
the galvanic circuit so long as they only act immediately on a 
single place of the circuit ; but if two different places were acted 
upon contemporaneously, a second current would be formed, 
which would necessarily, according to circumstances, more or less 
change the first." 

A 
" The equation S = 

L 
shows that the current of a galvanic circuit is subjected to a 
change, by each variation originating either in the magnitude of 
a tension or in the reduced length of a part, which latter is itself 
again determined, both by the actual length of the part, as well 
as by its conductibility and by its section." 



A HUNDRED TEARS AGO AND TO-DAY, 1 69 

Before closing this brief history of electrical invention 

I should eall your attention to a notable application 
made by Jacobi* in 1831, in the direction of electrotyp- 
ing, and a somewhat similar invention of. electro-plating 

made at a later date by Elkingtonf in 1838, and some- 
what later by Wright. J 

* I believe that the first notiee of Dr. Jacobi's discov- 
ery in England was the following communication sent 
to the Editor of the <k Annals of Electricity" and pub- 
lished on page 507, of Vol. 3, by Mr. Julian Guggs- 
worth. 

"I have just learned that Professor Jacobi is occupying him- 
self with a discovery which may. if in the end successful, prove 
of far more use than Daguerre's. He observed that the copper 
deposited by galvanic action on his plates of copper could, by 
certain precautions, be removed from those plates in perfect 
sheets which presented in relief, most accurately, every accidental 
indentation on the original plate. Following up this remark, he 
employed an engraved copper plate for his battery, caused the 
-it to be formed on it. removed it by some means or other ; 
he found that the engraving was printed thereon in relief (like a 
wood cut 1. and sharp enough to print from. Whether a repeti- 
tion of the process from this galvanically formed block will fur- 
nish, in its turn, a copper plate from which impressions can be 
thrown off, is not yet established. 

JULIAN GUGGSWORTH." 

Wormwood Scrubs, 
Feb. :». 1 

tTln- Messrs. Elkington took out a patent in connec- 
tion with Mr. Q. W. Barrett for a process for electrolyti- 

cally coating articles of copper and brass with zinc, on 
July 24, 1838. 

I Wright's inventions in electro-plating were based on 



1 70 ELECTRICITY, 

a fact published by Scheele, of the solubility of the ox- 
ide and cyanide of gold, silver and copper. I quote a 
passage from Scheele's Chemical Essays, pages 405 and 
406, from p. 20 of that interesting book, "The Art of 
Electro-metallurgy " by G. Gore. D. Appleton&Co., New 
York, 1884: 

' If, after these calces' [i. e. the cyanides of gold and silver] ' have 
been precipitated, a sufficient quantity of the precipitating 
liquor be added in order to redissolve them, the solution remains 
clear in the open air, and in this state the aerial acid [i. e. the 
carbonic acid], does not precipitate the metallic calx." 
Continuing, Mr. Gore says : 

" This statement suggested to Mr. Wright the probable suitabil-: 
ity of the cyanides of gold and silver, dissolved in solutions of the 
alkaline cyanides, for the purpose of electro-plating ; and he im- 
mediately took a solution, composed of chloride of silver dis- 
solved in aqueous ferro-cyanide of potassium, and quickly ob- 
tained what had never been acquired before, viz. a thick deposit of 
firm and white silver by electrolytic action. In all previous trials 
the coating of silver had either been very thin, or in a state of 
dark-coloured, loose powder, completely useless for the intended 
purpose. 

" The first article that received the successful coating was a 
small vase, and the next was a small figure of a kid. They were 
coated by Mr. Wright at his residence, and the process adopted 
was as follows : — A common, porous garden-pot, containing the 
silver solution, was placed in dilute sulphuric acid contained in 
an outer vessel ; the article to be coated was immersed in the in- 
ner liquid, and connected by a wire with a cylinder of zinc sur> 
rounding the porous cell, and immersed in the dilute acid. It was 
about a month after this that a solution of actual cyanide (not fer- 
ro-cyanide) of silver and potassium was first employed by Mr, 
Wright for the same purpose. It is true that cyanides in several 
forms had been used both for electro-coppering and silvering 
about sixteen months previously ; but that was by the simple 
immersion process, without the use of zinc, or a single cell or 
battery, and by that process no thick deposits can be obtained." 



A HUNDRED YEARS AGO AND TO-DAY. 17I 

Jacobi called his process galvanoplasty,*but it is now 
generally known as electrotyping. By moans of this 
process copies arc made of various objects such as met- 
als, or statues, in copper or other metals. 

In the process of electro-plating an electric current 
passing through a bath containing a solution of a metal- 
lic salt decomposes said solution and dissolves a plate of 
metal hung at the anode, or electro-positive terminal of 

* A translation of Professor Jacobi's original paper on 
"Galvanoplastik; or the Process of Cohering Copper into 
Plates, or Other Given Forms, by Means of Galvanic 
Action on Copper Solutions. By Dr. M. Jacobi, Privy 
Councilor to the Emperor of Russia, and Member of the 
Royal Academy of Sciences, of St. Petersburg, " appeared 
in p. 323 oi Vol. 7. of the Annals of Electricity. 

" The pages which I now submit to my readers contain such of 
my discoveries of the new application of the galvanic powers, as 
appear to be important with reference to practical and scien- 
tific individuals ; and which, in some measure, already has be- 
come so. It happened, whilst I was in Dorpart, in the month of 
February, 1837, prosecuting my galvanic investigations, that I 
discovered a striking phenomenon which presented itself in my 
experiments, and furnished me with perfectly novel views. By 
an attentive observation and persevering pursuit of this phenom- 
ena, 1 bood became convinced that in this simple fact there lay 
a completely new field of interest ; which by means of galvanic 
currents we iiii_ r ht be able to arrive at successfully ; but it was 
only by very gradual steps that I attained a knowledge of the 
simple conditions, OD which the results are depending." 

Also on page 495 of the same Volume : 
M In tie year l-:»7. whilst in Dorpart, I had a series of experi- 
carry <m. apon the strength and duration of galvanio 



172 ELECTRICITY, 

the source, and deposits it in an adherent coating over 
any electrically conducting surface placed in the bath 
and connected to the kathode, or electro-negative termi- 
nal of the source. By making the plate hung at the 
anode of the same metal as that dissolved in the bath, 
the strength of the solution in the bath is maintained 
constant and the process becomes a continuous one, the 
metal being dissolved from the plate at the anode as 
rapidly as it is removed from the solution of the bath. 

currents produced by an apparatus constructed upon similar 
principles ; but instead of copper plates I furnished myself with 
copper cylinders, surrounded by animal bladders, for the purpose 
of keeping the liquids separate. As these bladders became dam- 
aged by use, they were taken out, and gave occasion to inquire 
into the form in which the copper was reduced. It was found on 
the surface of the copper cylinders, and in the inner folds of the 
bladders, partly in thin bars and partly in large and small corns 
of crystalline texture, which to those beneath shewed not the 
least attachment. Afterwards, however, whilst continuing to re- 
move these corns, &c, it was found that they adhered more close- 
ly together, and required some force to separate them ; it was 
also found that the copper cylinder itself was completely covered 
with a layer of reduced copper, which, to my astonishment, was 
removed in large well-connected plates. As no mention had hith- 
erto been made of such regular formations of reduced copper, 
these corns, &c, were held of a high interest. I must confess, in- 
deed, that I was myself surprised, as I remarked at the time, that 
some fine file marks and indentations from hammer-blows, which 
were conspicuous on the surface of the copper cylinders, had, 
with the greatest degree of accuracy, given corresponding forms 
to the plates of reduced copper. This remarkable phenomenon 
was a strong proof of the conformation to the law by which cop- 
per is capable of being reduced, and which could not have been 
expected from the un-uniform productions which had previously 



A HUNDRED YEARS AGO AND TO-DAY. 1 73 

An important modern outgrowth of electro-plating - , 
or more correctly of electrolysis, is to be found in the 
extremely valuable invention ot the secondary or storage 
batter}' in 1859. The storage or secondary battery ot' 
Plante* consists essentially ot plates ot lead immersed in 
dilute sulphuric acid. By the passage ot an electric cur- 
rent through the acid, electrolytic decomposition takes 
place, and. by a process called '-forming- the phi 
which consists substantially in sending a current for a 
considerable length of time in one direction, and then 



beeu obtained. As the reduced plates acquire a certain decree of 
connection and firmness, there were hopes that, by a discernment 
of their management, these properties might be obtained in a 
Still higher degree ; and, finally, this humid method of forming 
copper plates on the surface of the cylinders, by galvanic action. 
immediately held out a practical result worthy of pursuing. 
How and by what manifold experiments these expectations shall 
be conformed with, and what will be acquired, in the course of 
performance, beyond that already done, cannot, in this place, be 
mentioned, where merely the description of the proceeding and 
the methods hitherto giYOD are intended." 

11 It appears, therefore, that linn coherent copper may be re- 
duced from its solution by the galvanic current. For this pur- 
ve employ an apparatus similar to that formerly described." 

Iant6 published his original papers M Researches sur 
larization Voltaique "in the 49th vol. of theComptes- 
rend 2. The studies described in tins pa- 

per were undertaken f<>r the purpose of comparing the 

I by voltameters <>f different 
metals placed in different solutions. As a result of these 
and later ini • he discovered the advan: 



174 ELECTRICITY, 






passing it through the cell in the opposite direction and 
repeating this change of direction many times, the lead 
plates become changed ; one of them becomes finally 
coated with lead peroxide, and the other with finely 
divided metallic lead. If now, when in this state, the 
charging current be discontinued, the cell will act as an 
independent source of electric current, and will pro- 
duce a current which will flow through the cell in the 
opposite direction to that of the current which was 
required to charge it. 

possessed by lead plates immersed in dilute sulphuric 
acid. He thus describes such a combination on pa^e 
14 of his book entitled "The Storage of Electric En- 
ergy." London: Whittaker & Co., 1887. 

" Lead covered with peroxide of lead, in water acidulated by 
sulphuric acid, acts in fact in a manner exactly the reverse to that 
of zinc in the same liquid. It tends to decompose the water, by 
absorbing hydrogen, and to become the positive pole of a cell, if 
it is connected with lead not oxydised, whilst pure zinc tends to 
decompose the water, by absorbing oxygen, and becomes the neg- 
ative pole of a cell in which it is opposed to another metal." 

"To this cause of the development of a secondary current by 
the voltameter of lead electrodes, we may add the effect produced 
upon the wire or plate of the negative pole on short-circuiting 
the voltameter after being submitted to the primary current." 

" The lead plate placed at the negative pole does not undergo, 
by the action of the primary current, as marked a change as that 
of the positive pole ; nevertheless, as lead is always more or less 
oxydised by exposure to the air, it is brought to a more perfect 
metallic state by the hydrogen which is manifestly the means of 
reducing the cell, and its tint changes from a bluish grey to a 
much lighter grey," 



A HUNDRED YEARS AGO AND TO-DAY. 175 

During this discharge of the cell the lead peroxide Pb 
:i one plate gives one of its atoms of oxygen and 
oxydizes the metallic lead on the other plate. When this 
oxydation becomes complete, both of the plates become 
covered with lead monoxide Pb ( ), and the cell c< 
to furnish an electric current. If, however, the charg- 
ing current be again sent through it, an atom of oxygen 
ain transferred from one plate to the other leaving 
the first plate as before covered with spongy lead and 
the other with lead peroxide of Pb 8 . By such a stor- 
cell, a convenient means is provided for practically 
ring the energy of the electric current. 
I have described the operation of charging the cell 
insisting essentially in the transference of an atom 
of oxygen from one of the plates to the lead monoxide 
Pb 0, on the other plate, whereby one of the plates be- 
comes covered with spongy lead and the other with lead 
peroxide Pb 8 . In reality, this is but the final result, 
intermediate compounds being formed with which I will 
not burden you this evening. 

I wish at this point to call your attention to the fact 
that a mnot any more properly be said 

to store electricity, than a music box can be said to 
store sound when mechanical power is applied to wind 
What the storage battery actually 
stores is the energy of the charging current. It acts as 
.ice whereby ip by effecting 

chemical decomposition, such energy being transformed 



1 76 ELECTRICITY, 

from mechanical energy to chemical potential energy, 
In discharging the storage battery this chemical poten 
tial energy becomes liberated and appears as electric 
energy, just as it does in the voltaic cell. 

Plante's original battery was greatly improved by 
Faure in 1880, who, by spreading oxide of lead over the 
surface of the plates, greatly reduced the time required 
for forming the plates. 

A very bright future is, in all probability, in store for the 
storage battery. Much, however, requires to be effected 
before it can take its place in the work of the world on a 
very extended scale. Considerable improvements, how- 
ever, are being made in this direction, and, we may reason- 
ably expect in the near future a better storage battery. 

I have in this exceedingly brief and somewhat im- 
perfect manner traced with you the progress made in 
electricity, from the time of the birth of the great idea of 
Thales until the present day. Although I know how 
dangerous it is even under the most favorable circum- 
stances to assume the position of a prophet, yet I 
desire to venture a few suggestions concerning the 
great things that it seems to me electric science has in 
the near future for the human race. These to my mind 
are briefly as follows : — 

(1.) A cheaper means for the production of electricity 
than is now possible by burning coal for the driving 
power of a steam engine, which in its part turns a 
dynamo-electric machine. 



A HUNDRED YTARS AGO AND TO-DAY. Iff 

This invention will, probably, be found in some im- 
provement in thermo-electricity, whereby coal will be 
burned directly to produce electricity, and not, as now, 
through the double intervention of a steam engine and 
dynamo. 

i The entire replacement of the steam engine by the 
electric motor. 

I do not think it unreasonable to believe that many 
in my audience to-night will live to see the steam 
engine relegated to the scrap pile as antiquated, and, 
possibly, even to hear it spoken of in their times as 
an incredible instance of how an otherwise bright age 
should have remained satisfied for so long with such a 
clumsy contrivance for the conversion of energy. 

(3). The successful solution of the problem of aerial 
navigation, effected, possibly, by means of the electric 
motor, and being rendered possible as a result of im- 
provements in the economical production of electricity. 
To my mind this problem only needs for its successful 
solution, means for concentrating great power in small 
weight. 

(4). The replacing of the electric light, that is the pres- 
ent electric light, with its preponderance of useless and 
injurious low heat ra; te species of electrically 

produced light which shall possess a smaller propor- 
tion of the useless heat rays and a larger proportion n[ 
the desired light rays. Though this discovery may 
come by the discovery of some means of producing cold 



I78 ELECTRICITY, 

light by ©hemical phosphorescence, yet it seems more 
probable that it will be by means of physical phospho- 
rescence, or by means of molecular bombardment as 
pointed out by Nikola Tesla in his classic experiments 
on the effects produced by alternating currents of extra- 
ordinary frequency and difference of potential. 

(5). A more intelligent means than are now adopted 
in the therapeutical applications of electricity to the cur- 
ing of diseases, whereby human life may be considera- 
bly prolonged, and human suffering lessened. 

In concluding this very brief survey of the electric field 
I am reminded of a charming story that I remember 
reading in my early childhood. If you will pardon me 
I will relate the story as I remember it. 

There once lived in the city of Bagdad a widow, who 
had an only son named Aladdin. Aladdin became the 
owner of a magic lamp which possessed the remarkable 
power of bringing to the aid of its owner the services of 
a powerful genie. No matter what service Aladdin 
wished, he had but to rub the lamp and the genie ap- 
peared, and gratified him. By its means he could hear 
the faintest whisper uttered thousands of miles away. 
By it he could annihilate time and distance, and be 
transferred, in the twinkling of an eye, to the tops of the 
highest mountains around Bagdad. 

Do you not agree with me that Thales, at least poten- 
tially, rediscovered this wonderful talisman ; for, when 
he rubbed the bit of amber, did he not call to the aid of 






a HUNDRED TEARS AGO AND TO-DAY. l~ | 

the world the services of a :nore powerful than 

the slave 'amp? Cannot the genius < tricity 

hear the fail hisper uttered hundreds 

of miles awa not by its means carry on 

communication with foreign lands under the bed of the 
Can we not by it annihilate time and distance 3 
And if the genius has done so much for 

the world during the time that we ha d his works, 

does it seem that some oi the things which I have 
pointed out to you as possibilities in the near future 
are n r all, so extremely improbable ? 

Perhaps I may be pardoned if I add to the prophe- 
cies made at the close of the Brooklyn lecture in i> :. 
a subsequent prophecy, prepared for an article printed 
in the January number of this year's AfcC/ure's Maga- 
entitled " The Edge oi the Future."' It contains 
a brief statement of what appears to me may be ex- 
ted in the future, and most of it in the not too 
distant future. 

"In the nearer foreground I see a practical method 
for the production of electricity directly from the 
burning of coal. This achieved, there nee 
follows the universal adoption of the electric motor 
as a prime mover; the relegation oi the steam-engine 
to the scrap-heap, and the almost immediate realiza- 
tion of the airship as a means of transportation. 

"Assuming the c, nical affinity to lie in 

the unlike electric charges of tin* combining atoms, 
I see the practical realization of electric synth 



i8o 



ELECTRICITY. 



whereby wholesome food-products will be directly 
formed under the potency of electric affinities. I 
see, too, a marked advance in electro-therapeutics, 
whereby human life will be prolonged and its suffer- 
ings alleviated. Diagnosis and prognosis will be 
profoundly aided by exact electrical measurements 
of the various organs of the human body as regards 
their electromotive force and resistance. The electro- 
therapeutist of the future will employ electric charges 
and currents for restoring the normal charges and 
currents of the body, as well as for the stimulation 
of nervous or muscular tissues. 

" Back of these achievements I discern a practical 
apparatus for seeing through a wire — i.e., a device 
for looking into a receiver at one end of a metallic 
wire and seeing therein a faithful reproduction of 
whatever optical images are impressed on a trans- 
mitter at the other end — even though thousands of 
miles intervene. I see the possible use of the step- 
down transformer for the preparation of a road-bed 
or road-surface by the vitrification, in situ, of clay or 
other suitable soil, by the intense heating power of 
enormous currents of electricity. 

" These things I believe I see with fair distinctness. 
In the further background I faintly see, dimly out- 
lined through the clouds, an apparatus for the auto- 
matic registration of unwritten, unspoken thought, 
and its accurate reproduction at any indefinite time 
afterwards." 

THE END, 



APPENDIX. 



Note. — There can be no doubt but that Gilbert's 
success in the domain of electricity was due largely 
to his methods, which, to a great extent, were those 
formulated by Bacon. 

Credit has very properly been awarded to Bacon 
for the services he thus rendered physical science by 
the clear manner in which he pointed out the method 
that should be adopted by the scientific investigator ; 
viz., the persistent, intelligent interrogation of nature 
as opposed to pure speculation. A danger exists, 
however, in going too far in the amount of such 
credit. 

nil the preceding quotation from the u Library 

ul Knowledge/* on Bacon's u Novum Organon 

itiarum," one might well imagine that there had 

been no line of investigation of nature up to this 



182 



APPENDIX. 



time. Such, however, was far from being true. The 
methods of scientific investigation have been pretty 
much the same in all ages. Bacon by no means 
pointed out an entirely new road leading to the Mys- 
teries of the Temple of Nature. It is true there were 
no well-defined, beaten broad-ways. Its travellers 
had been too few. There w r as only here and there a 
straggler who had wandered far into the hitherto 
unexplored land, and so few had followed his hesi- 
tating and uncertain footsteps ihat time had almost 
obliterated them. No wonder, therefore, that to 
many it seemed that Bacon was pointing out an 
entirely new way, and even to the present day he is 
given, I think, too much praise. I quite agree with 
Prof. Oliver Lodge, who thus refers to the matter in 
a very able book entitled " The Pioneers of Science" 
(London, Macmillan & Company, 1893, pp. 404). He 
is speaking of those great pioneers in science who, 
early in the dawn of true science, followed paths that 
are now broad and high ways. 

The quotation is to be found on page 141. 

"Of Lord Bacon, who flourished about the same 
time (a little later), it is necessary to say something, 
because many persons are under the impression that 
to him and his Novum Organon the reawakening of 
the world, and the overthrow of Aristotelian tradition, 
are mainly due. His influence, however, has been 
exaggerated. I am not going to enter into a dis- 



APPENDIX. 183 

cussion of the Novum Organon y and the mechanical 

methods which he propounded as certain to evolve 
truth it patiently pursued; for this is what he thought 
he was doing — giving to the world an infallible recipe 
for discovering truth, with which any ordinarily in- 
dustrious man could make discoveries by means n\ 
collection and discrimination of instances. You will 
take my statement for what it is worth, but I assert 
this: that many of the methods which Bacon lays 
down are not those which the experience oi mankind 
has found to be serviceable ; nor are they such as a 
scientific man would have thought of devising. 

"True it is that a real love and faculty for science 
are born in a man, and that to the man of scientific 
capacity rules of procedure are unnecessary ; his own 
intuition is sufficient, or he has mistaken his vocation, 
— but that is not my point. It is not that Bacon's 
methods are useless because the best men do not 
need them ; if they had been founded on a careful 
study of the methods actually employed, though it 
might be unconsciously employed, by scientific men 
— as the methods of induction, stated long after by 
John Stuart Mill, were founded — then, no doubt, 
their statement would have been a valuable service 
and a great thing to accomplish. But they were not 
this. They are the ideas of a brilliant man of letters, 
writing in an age when scientific research was almost 
unknown, about a subject in which he was an ama- 



184 APPENDIX. 

teur. I confess I do not see how he, or John Stuart 
Mill, or any one else, writing in that age, could have 
formulated the true rules of philosophizing ; because 
the materials and information were scarcely to hand. 
Science and its methods were only beginning to grow. 
No doubt it was a brilliant attempt. No doubt also 
there are many good and true points in the statement, 
especially in his insistence on the attitude of free and 
open candour with which the investigation of nature 
should be approached. No doubt there was much 
beauty in his allegories of the errors into which men 
were apt to fall — the idola of the market-place, of the 
tribe, of the theatre, and of the den ; but all this is 
literature, and on the solid progress of science may 
be said to have had little or no effect. Descartes's 
Discourse on Method was a much more solid produc- 
tion." 

" You will understand that I speak of Bacon purely 
as a scientific man. As a man of letters, as a lawyer, 
a man of the world, and a statesman, he is beyond 
any criticism of mine. I speak only of the purely 
scientific aspect of the JVovum Organon, The Essays 
and The Advancement of Learning are masterly pro- 
ductions ; and as a literary man he takes high rank." 

Note also in this connection the opinion of Prof. 
Draper, quoted by Lodge, page 143, from the former's 
1 History of Civilization in Europe,' vol. ii. page 259. 

" The more closely we examine the writings of 






APPENDIX. 185 

Lord Bacon, the more unworthy does he seem to have 
been of the great reputation which has been awarded 
to him. The popular delusion to which lie owes so 
much originated at a time when the history of science 
was unknown. They who first brought him into 
notice knew nothing of the old school of Alexandria. 
This boasted founder of a new philosophy could not 
comprehend, and would not accept, the greatest of 
all scientific doctrines when it was plainly set before 
his eyes. 

" It has been represented that the invention of the 
true method of physical science was an amusement 
of Bacon's hours of relaxation from the more labori- 
ous studies of law, and duties of a court. 

" His chief admirers have been persons of a literary 
turn, who have an idea that scientific discoveries 
are accomplished by a mechanico-mental operation. 
Bacon never produced any great practical result him- 
self, no great physicist has ever made any use of his 
method. He has had the same to do with the devel- 
opment of modern science that the inventor of the 
orrery has had to do with the discovery of the mech- 
anism of the world. Of all the important physical 
there is not one which shows that its 
author made it by the Baconian instrument. 

"Newton never seems to have been aware that he 
was under any obligation to Bacon. Archimedes, 
and the Alexandrians, and the Arabians, and Leo- 



1 86 



APPENDIX. 



nardo da Vinci did very well before he was born ; 
the discovery of America by Columbus and the cir- 
cumnavigation by Magellan can hardly be attributed 
to him, yet they were the consequences of a truly 
philosophical reasoning. But the investigation of 
Nature is an affair of genius, not of rules. No man 
can invent an organon for writing tragedies and epic 
poems. Bacon's system is, in its own terms, an idol 
of the theatre. It would scarcely guide a man to a 
solution of the riddle of ^Elia Lselia Crispis, or to that 
of the charade of Sir Hilary. 

' k Few scientific pretenders have made more mis- 
takes than Lord Bacon. He rejected the Copernican 
system, and spoke insolently of its great author ; he 
undertook to criticise adversely Gilbert's treatise De 
Magnete ; he was occupied in the condemnation of 
any investigation of final causes, while Harvey was 
deducing the circulation of the blood from Aqua- 
pendente's discovery of the valves in the veins ; he 
was doubtful whether instruments were of any ad- 
vantage, while Galileo was investigating the heavens 
with the telescope. Ignorant himself of every branch 
of mathematics, he presumed that they were useless 
in science but a few years before Newton achieved 
by their aid his immortal discoveries." 



INDEX, 



Advantages possessed by elec- 
tric motors, 161 

Affluent electric matter, Nollet's 
hypothesis of, 40, 41 

Aladdin's wonderful lamp, re- 
discovery of. 17S 

Alkalies, compound nature of, 
discovery by Davy, 11 3-1 16 

Alkaline earths, Davy's discov- 
ery of the compound nature 
of, 113-116 

Allamandand Muschenbroeck's 
experiment on Leyden jar, 

43, 44 
Alphabet, Morse system. 147 
Alternating - current distribu- 
tion, 64, 65 
Amber, attractive nature of, 

mentioned by PI in 
Amber, attractive nature, men- 
tioned by Gaffendus, Digby, 
and Brown. 
Amber, electrified by friction, 

16 
Ampere's discovery. 143. 144 
Ampere's discovery, Silliman 

on, 143, 144 
Anode, definition of, 171 
Anomalous magnetization, 63 
Arc light, voltaic, the first, 117— 
119 

, voltaic, intense heat of, 
119 
Area of protection afforded by 
lightning-rods, 102 



Area of protection afforded by 
lightning rods, difficulty of 
correctly estimating, 102 

Articulating telephone, inven- 
tion of, by Bell, 163 

Atlantic cable. Field's first an- 
nouncement as to the success- 
ful laying of, 14S-151 

Atmospheric electricity, De Ro- 
mas' experiments with. 82, 83 

Atmospheric electricity. Frank- 
lin's experiments with, 79-S2 

Atmospheric electricity, Rich- 
man's fatal experiments with, 
S4- 

B 

Bacon's inductive method of 
studying natural phenomena, 
25-27 

Bacon's " Novum Organon," 26 

Bath, plating, 172 

Bell, invention of articulating 
telephone by, 163 

Benediti, 12 

Benediti, Piccolomini, Galileo, 
independent discovery of the 
laws of motion by, 12 

Biographical notice of Harris 
by Tomlinson, 90-94 

Brett's dynamo-electric ma- 
chine, 155 

Brush-and-spray discharge, Tes- 
la's, 60 

Bumper, electrified, use of, by 
Franklin, 34 



1 88 



INDEX. 



Cable, first submarine, 14S 

Carbon arc light exhibited at 
Royal Institution, Davy's de- 
scription of, 118-120 

Carbonization of fibrous mate- 
rial oi the filament of incan- 
descent electric lamp, 156 

Carbonizing process for fila- 
ment of incandescent electric 
lamp, 156 

Carlisle and Nicholson, discov- 
ery of electrolysis by, ill, 
1 12 

Cavallo on lightning protection, 
84 -So 

Cavallo on the invention of the 
Leyden jar, 51, 52 

Cavendish and Watt, indepen- 
dent discovery of composition 
of water by, 13 

Celestial sphere, division of, into 
five zones by Thales, 16 

Chamber of incandescent elec- 
tric lamp, 156 

Charging of storage battery, 175 

Circuits, non-electrical, Wat- 
son's so-called, 29, 30 

Clarke's dynamo-electric ma- 
chine, 154 

Conducting power, electrical, 
Watson's experiments on, 29- 

Conducting power, influence of, 
on efficiency Of lightning- 
rods, 98 
Conduction, electric, modern 

views concerning, 72-70 
Conduction, electric, old views 

concerning, 71, 72 
Conductive discharge, 61, 62 
Contraplex telegraphy, 151 
Convective discharge, 63 
Counter-electromotive force of 

electric motor, \0o 
Counter-electromotive force of 

voltaic cell, 139 
Cookcs' claim to priority of in- 



vention of the electric tele- 
graph, 145 

Cunaeus, independent invention 
of Leyden jar by, 43, 44 

Cunaeus' letter to Reaumur con- 
cerning effects of discharge of 
Leyden jar, 47, 48 

D 

Dal Negro's electric motor, 160 

Dal Negro's magneto-electric 
machine, 154 

Daniell's constant cell, descrip- 
tion of, 140, 141 

Daniell's constant cell, impor- 
tance of, to the operation of 
the Morse system of telegra- 
phy, 139 

Daniell's description of his cell 
to Faraday, 140, 141 

Daniell's double-fluid cell, 140 

Daniell's invention of the con- 
stant voltaic pile, 135 

Davy, discovery of potassium 
by, 1 13-1 1 5 

u De Magnete," Gilbert's, 22 

"De Magnete," Gilbert's pub- 
lication of, in 1600, 22 

Definition of acoustic reso- 
nance, 67 

Definition of anode, 171 

Definition of electric resonance, 

67 
Definition of kathode, 171 
De Romas, experiments of, 

with atmospheric electricity, 

82, S3 
De Romas' kite, 81, 82 
Desaguliers on the state of the 

electric science in 1741, 52-54 
Description of electro-plating, 

171, 172 
Diamonds, sapphires, and other 

substances electrified by fric- 
tion, list of, 23 
Differential calculus, invention 

of, 13 
Diplex telegraphy, 151 



INDEX. 



189 



Discharge, brush-and-spray, 

Tesla's, 60 
Discharge, conductive, 61, 62 
Discharge, convective, 63 
Discharge, disruptive, 62 
Discharge, impulsive or oscil- 
latory, of lightning, 91, 92 
Discharge, oscillatory, of Ley- ! 
den jar, Henry's discovery of, 
61, 62 
Discharge, Tesla's flaming, 57 
Discharge, Tesla's sensitive- 
thread, 56 
Discharge, Tesla's streaming, 

59 

Discharges of Leyden jar and 
lightning, resemblance be- 
tween, 97 

Discharges, lightning, oscilla- 
tory character of, 97 

Discharges of lightning, 

Lodge's classification of, 91, 
92 

Discharges, oscillatory, Hertz 
on, 66, 67 

Discharges, oscillatory, of Ley- 
den jar, Lodge on rate of, 70- 
72 

Discharging of storage battery, 

175 

Discovery of the compound na- 
ture of alkalies and the alka- 
line earths, Davy's announce- 
ment of, to the Royal Society, 
113-116 

Discoveries of Galvani, 104- 
107 

Disruptive discharge, 62 

Distribution, alternating-cur- 
rent system of, 64, 65 

Distribution by alternating cur- 
rents, advantages possessed 
by, 65 

Dots and dashes of the Morse 
alphabet, how produced, 147 

Double-fluid cell, Daniell's, 140 

Dual character of electric ex- 
citement, 42 



Du Fay's double-fluid electrical 
hypothesis, 36-38 

Du Fay's single-fluid electrical 
hypothesis, Priestley on, 37 

Duplex telegraphy, invention 
of, 150 

Dynamo-electric machine, early 
experiments of Faraday con- 
cerning the principles of 
operation of, 134 



Early Leyden jar discharges 
through long circuits, 30, 31 

Eclipses, nature of first, ob- 
served by Thales, 16 

Edison's invention of the phono- 
graph, 164 

Efficiency of lightning-rods, 96 

Effluent electric matter, Nollet's 
hypothesis of, 40, 41 

Effluvia, electric, Grey on, 29 

Effluvia, electric, Nollet's hy- 
pothesis of, 40, 41 

Electric conduction, modern 
views concerning, 73-79 

Electric conduction, modern 
conception of, 64 

Electric conduction, old views 
concerning, 71, 72 

Electric arc light, Staite's, 125- 
127 

Electric effluvia, Grey on, 29 

Electric effluvia, Nollet's hy- 
pothesis of, 40, 41 

Electric force, unrecognized for 
a long time, 20 

Electric light, extensive use, 

155 

Electric light, Faraday on im- 
practicability of, 125 

Electric light, Faine's, 128-133 

Electric motor, advantages 
possessed by, l6l 

Electric motor, counter-electro- 
motive force of, 160 

Electric motor, Dal Negro's, 
160 



190 



INDEX. 



Electric motor, firts invention 

of, 158 
Electric motor, Jacobi's, 158, 159 
Electric motor, Martin and 

Wetzler on, 157 
Electric motor, Page's, 158, 159 
Electric motor, Ritchie's, 160 
Electric motor, self-regulating 

power possessed by, 160 
Electric motor, the more im- 
portant relative advantages 
possessed by, 161, 162 
Electric motor, why not at first 
commercially successful, 158, 

159 
Electric motor, Wilde's, 160 
Electric radiation, 68 
Electric resonance, definition 

of, 67 
Electric resonance, Hertz on, 

67 
Electric telegraph, Henry's 

early invention of, 138, 139 
Electric telegraph, Morse's 

early conception of, 145-147 
Electric telegraph, Wheat- 
stone's claim to priority of 

invention of, 145 
Electric transmission of power, 

advantages possessed by, 161, 

162 
Electric waves, interference of, 

69, 70 
Electrical conducting power, 

Grey's experiments concern- 
ing, 28-30 
Electrical hypothesis of Nollet, 

40, 41 
Electrical jack, use of, by 

Franklin, 33 
Electricity, atmospheric, De 

Romas' experiments with, 82, 

83 

Electricity, atmospheric, Frank- 
lin's experiments with, 79-82 

Electricity, atmospheric, Rich- 
man's fatal experiments on, 
84-87 



Electricity, first recorded ex- 
periment in, by Thales, 16 

Electricity, first recorded exper- 
iment in, by Thales, signifi- 
cation of, 16 

Electricity produced by the 
friction of tourmaline, 19, 20 

Electricity, thermo-, Siebeck's 
discovery of, 165 

Electrics and non-electrics, Gil- 
bert's classification of, 22, 23 

Electrified bumper, use of, by 
Franklin, 34 

Electro-magnetic inertia, in- 
fluence of, on lightning dis- 
charges, 98 

Electro-magnet, invention of, 
by Sturgeon, 135 

Electro-magnetic telegraph, 
type of invention of, 144 

Electro-magneticwaves, Hertz's 
conceptions of, 67 

Electro-magnetism and the vol- 
taic cell, Oersted's discovery 
of relation existing between, 
142 

Electro-magnet, invention of, 
by Henry, 135 

Electro-magnets, Henry's, 136, 

137 

Electromotive force, counter-, 
of voltaic cell, 139 

Electro-plating, circumstance 
leading to Wright's improve- 
ments in, 170 

Electro-plating, description of, 
171, 172 

Electro-plating, Elkington's in- 
vention of, 169 

Electro-plating, Wright's inven- 
tion of, 169 

Electrotyping, invention of, by 
Jacobi, 169 

Electrocution of a turkey, 34 

Electrolysis, discovery of, by 
Nicholson and Carlisle, in, 
112 

Electroscope, Galvani's frog, 104 



INDEX. 



I 9 I 



Elkington on the use of mag- 
neto-electric machine in 
electro-plating, 125 

Elkington's invention of electro- 
plating, 169 

Elkington's invention of electro- 
plating, date of patent for, 
iS. 169 

Environment, effect of, on the 
development of inventions, 8 

Euclid, 47th proposition of, in- 
vention anticipated by Thales, 
16 

Excitement, electric, dual char- 
acter of, 42 

Exhaustion of incandescent 
electric lamps, 156 

Experiment of Theophrastus, 
19 



Faraday, discovery of magneto- 
electric induction by, 127 

Faraday's early dynamo-elec- 
tric machine, 153 

Faraday's early experiments on 
the principles involved in the 
operation of dynamo-electric 
machines, 134 

Faraday's experimental re- 
searches, 152, 153 

Faure storage battery, 176 

Field, Cyrus W., first Atlantic 
cable, 143 

Field's first announcement of 
the successful laying of the 
Atlantic cable, 14S-151 

Filament of incandescent elec- 
tric lam; 

First announcement of Ohm's 
discovery, 167, 168 

First submarine cable, 14S 

Flaming discharge, Tesla's, 57 

Flaming discharge, Tesla's, 
conditions necessary for pro- 
ducing. 

Flashes, lightning, oscillatory 
character of, 97 



Fleming's " Electric Current 
Transformer," quotations 
from, 74-79 

Forming of plates of storage 
battery, 173 

Franklin, circumstances leading 
to the invention of the light- 
ning-rod by, S7, 88 

Franklin, directions of, concern- 
ing the construction of light- 
ning-rods, 81, S2 

Franklin, spirits fired by dis- 
charge across the Schuylkill 
River by, 33 

Franklin's kite, 79, So 

Franklin's single-fluid hypothe- 
sis of electricity, 3S-41 

Frog, Galvani's, 103 

Fruitful and timely inventions, 
9, 10 



Gaffendus, Digby, and Brown, 
attractive nature of amber 
mentioned by, 22 

Galileo, 13 
! Galileo, Benediti, Piccolomini, 
independent discovery of laws 
of motion, 12 

Galvani, discoveries of, 103-107 

Galvani's frog, 103 

Galvani's frog electroscope, 104 

Galvani's frog, stories told con- 
cerning, 104-106 

Galvanic multipler, Sweigger's, 
136 

Galvanoplastic process, Jaco- 
bi's, 171 

Galvanoplastics, 171 

Galvanoplasty, 171 

Gilbert, physician to Queen 
Elizabeth, electrical observa- 
tions of, 22 

Gilbert's classification of elec- 
trics and non-electrics, 22, 23 

Gilbert's " De Magnete," 22 

Gilbert's employment of the 
inductive method, 24, 25 



192 



INDEX. 



Gramme's dynamo-electric ma- 
chine, successful invention of, 

Grey on electric effluvia, 29 

Grey's experiments on electri- 
cal conducting power, 28-30 

Grey, Stephen, electrical re- 
searches of, 27, 28 

Grove on electric light, 123, 
214 

Gutter-spouts, metal roofs, and 
cornices, disposition of, as re- 
gards lightning-rods, 93, 94 

H 

Harmonic telegraphy, 152 

Harris on lightning protection, 
87-89 

Harris, Tomlinson's biographi- 
cal notice of, 90-94 

Henry's analysis of the dy- 
namic phenomena of the Ley- 
den jar, 61, 62 

Henry's discovery of the oscil- 
latory character of the dis- 
charge of a Leyden jar, 61, 62 

Henry's early invention of the 
electric telegraph, 138, 139 

Henry's electro-magnets, 136, 

137 

Henry's electro-magnets, ap- 
plication of Sweigger's prin- 
ciples to, 138, 139 

Henry's galvanic multiplier, 135 

Henry's invention of the elec- 
tro-magnet, 135 

Hertz on oscillatory discharges, 
66, 67 

Hertz's discoveries, Tanzel- 
mann on, 68-70 

Hertz's theory of electro-mag- 
netic waves, 66-70 

High potential discharges, Tes- 
la's experiments on, 55-60 

Hiorth's dynamo-electric ma- 
chine, 155 

Holmes' dynamo-electric ma- 
chine, 155 



Humphry Davy's discovery of 

potassium, 113-115 
Hypothesis, double-fluid, of Du 

Fay, 36-38 
Hypothesis, Nollet's, of affluent 

electric matter, 40, 41 
Hypothesis, Nollet's, of effluent 

electric matter, 40, 41 
Hypothesis, Nollet's, of electric 

effluvia, 40, 41 
Hypothesis of electricity, Nol- 

let, 40, 41 
Hypothesis, single-fluid, of elec- 
tricity, Franklin's, 38-41 

I 

Ideas, birth of, Youmans on, II, 
12 

Immature or incomplete inven- 
tions, 9, 10 

Impulsive or oscillatory light- 
ning discharge, 91, 92 

Incandescent electric lamp, 
chamber of, 156 

Incandescent electric lamp, fila- 
ment of, 156 

Incandescent electric lamp, life 
of, 156 

Incandescent electric lamp, in- 
vention of, 156 

Incandescent electric lamp, 
many inventions concerned 
in the production of, 156 

Incandescent electric lamps, ex- 
haustion of, 156 

Incandescent lamp, Tesla's high- 
frequency discharge, 59, 60 

Incomplete or immature inven- 
tions, 9, 10 

Induction, magneto-electric, 
discovery of, by Faraday, 127 

Induction, self-, influence of, on 
efficiency of lightning-rods, 98 

Inductive method, employ- 
ment of, by Gilbert, 24, 25 

Inertia, electro-magnetic, in- 
fluence of, on lightning dis- 
charges, 98 



INDEX. 



•93 



Interference of electric waves, 

69, 70 
Invention of arc light, type of, 

134 

Invention of articulating tele- 
phone by Reiss. 163 

Invention of articulating tele- 
phone by Reiss, type of, 164 

Invention of electro-magnetic 
telegraph, type of, 144 

Invention oi electric motor, 
type of, 158 

Invention of incandescent elec- 
tric lamp, character of, 156 

Invention of Leyden jar, type 
of, 43 

Invention of lightning-rods, 
thoughts or circumstances 
leading to Franklin's, 87, 
88 

Invention of secondary battery, 

173 
Invention of storage battery, 

173 

Invention of telephone, 165 

Invention of the electric tele- 
graph, Cookes' claim as to 
priority of, 145 

Invention of the electric tele- 
graph, Steinheil's claim as to 
priority of, 145 

Invention of the lightning-rod 
by Franklin, So 

Invention of the voltaic pile, 
107, no 

Invention of the voltaic pile, 
type of, 108, 109 

Inventions, classification of, 9 

Inventions, development of, af- 
fected by environment, 8 

Inventions, electrical, possible 
future, 176, 177 

Inventions, immature or incom- 
plete, 9, 10 

Inventions, immature or incom- 
plete, influence of, 9, 10 

Inventions, mature and timely, 
10 



Inventions, untimely and un- 
fruitful, 9, 10 

Inventions, untimely and un- 
fruitful, influence of, 9, 10 

Investigations of Volta, 107- 
1 11 

Iron z's. copper for the con- 
struction of lightning-rods, 
102 

j 

Jack, electrical, use of, by 
Franklin, 33 

Jacobi, invention of electro- 
typing by, 169 

Jacobi on galvanoplasty, 171, 
172 

Jacobi's dynamo-electric ma- 
chine, 155 

Jacobi's electric motor, 157, 158 

Jacobi's invention, first an- 
nouncement of, in England, 
169 

Jar, Leyden, early extravagant 
assertions as to the physio- 
logical effects of, 48 

Jar, Leyden, experiment of 
Muschenbroeck and Alla- 
mand on, 43, 44 

Jar, Leyden, independent in- 
vention of, by Cunaeus, 43, 

44 

Jar, Leyden, invention of, by 
Von Kleist, 42 

Jar, Leyden, Priestley on inven- 
tion of, 43 

Jar, Leyden, type of invention 
of, 43 

K 

Kathode, definition of, 171 

Kite, De Romas', 81, 87 

Kite, Franklin's, 79, 80 

L 

Lamps, incandescent, Tesla's 
high-frequency discharge, 59, 
60 

Law, Ohm's, 167 



1 94 



INDEX. 



Laws of motion, independent 
discovery of, by Galileo, Bene- 
diti, and Piccolomini, 13 

Leibnitz, Newton, independent 
invention of differential cal- 
culus, 13 

Leyden jar, Cavallo on the in- 
vention of, 51, 52 

Leyden jar, early discharges of, 
through long circuits, 30, 31 

Leyden jar, early extravagant 
assertions concerning effects 
of, 46 

Leyden jar, independent inven- 
tion of, by Cunseus, 43, 44 

Leyden jar, invention of, by 
Von Kleist, 42 

Leyden jar, Nollet's experiment 
on the physiological effects 
of, 47, 48 

Leyden jar, probable reasoning 
leading to the invention of, 
50 

Leyden jar, type of invention 

of, 43 

Leyden phial, invention of, by 
Von Kleist, 42, 43 

Lieberkuhn, announcement of 
Von Kleist's invention by, 
44-46 

Life of incandescent electric 
lamp, 156 

Light, electric, Grove on, 123, 
214 

Light, electric, Grove on the 
economy of, 123, 124 

Light, Staite's electric arc, 125- 
127 

Light, voltaic carbon arc, Da- 
vy's exhibition of the splen- 
dors of, 117, 118 

Lightning discharges, oscilla- 
tory character of, 97 

Lightning protection of build- 
ings, early ideas concerning, 
1795, 84-86 

Lightning protection, Harris 
on, 87-89 



Lightning-rod, area protected 
by, 102 

Lightning-rod, invention of, by 
Franklin, 80 

Lightning-rods, action of points 
on, 100, 101 

Lightning-rods, efficiency of, 96 

Lightning-rods for ships, Har- 
ris's system of, 87-S9 

Lightning-rods, influence of 
conducting power on efficien- 
cy of, 98 

Lightning-rods, influence of 
sectional area on efficiency, 
100 

Lightning-rods, influence of 
surface on efficient action of, 
100 

Lightning-rods, necessity for 
ground connection of, 99 

Lightning-rods, possible danger 
from proximity to, during dis- 
charges, 99 

Lightning-rods, tests as to elec- 
trical continuity of, 101 

Lightning-rods, tests of elec- 
trical continuity sometimes 
misleading, 102 

Lodge on the practical vs. the 
theoretical in lightning rod 
protection, 95-102 

Lodge's classification of light- 
ning discharges, 91, 92 

Lodge, modern views concern- 
ing the construction of light- 
ning-rods, 90-95 

Lodge on rate of oscillation of 
Leyden jar discharge, 70-72 

Lyncurium, electrification pro- 
duced by friction of, 19 

M 

Machine, Brett's dynamo-elec- 
tric, 155 

Machine, Clarke's dynamo-elec- 
tric, 154 

Machine, Dal Negro's magneto- 
electric, 154 



INDEX. 



'95 



Machine, Hiorth's dynamo- 
electric, 155 

Machine, Holmes' dy namo-elcc- 

trie, 1 55 

Machine, lacobi's dy namo-elcc- 
1 5 5 

Machine, Page's dynamo 1 

trie. 155 

Machine. Pixey's dynamo-elec- 
tric, 154 

Machine. Pix< \ *s magneto* 

electric, 154 
Machine. Saxton's dynamo- 
electric, 1 54 

Machine. Sturgeon's dynamo- 
electric, 
Machine, Wheats tone's dyna- 

mo-elect 1 ic, 1 55 

Machine, Wilde's dynamo-elec- 
tric, 155 

Magazine, Philosophical, on 
Davy's exhibition oi the vol- 
taic arc. 1 21 

Magnetization, anomalous, 63 
Magnetization produced 03 
dilatory discharge, character 
of, 
Magneto-electric induction, dis- 
covery of, by Faraday, 127 
Magneto-electric machine, e 
use in producing electric light, 
131, 133 
Magneto-electric telephone, 163 
Martin and Wetzler on the elec- 
tric motor, 1 57 
Matter, affluent eh let's 

hvpoth' . 41 

Matter, effluent electric, Nol- 

S hvpoth' . . 41 

Mature <>r timely invention- 
Mature or timely inventions, in- 
fluence of, 10. 1 1 
Miletus, birthplace - 1 1 

ei ning elcc- 

M >rse telegraphic 
Morse's invention of the el© 
telegraph 



Motion. independent 

discovei y of, by Galileo, Be- 
nediti, and Piccolomin 

Multiplex telegraphy, 1 

Multiplier, galvanic. 1 len: , 
135 

Muschenbroeck, Watson on the 

experiments of, 1 ;. 1 1 
Muschenbroeck's experiment on 

Leyden jar. 43, 1 1 

N 
Natural phenomena, Bacon's 

inductive method o! studying, 

New electrical machine, Faia- 
dav's. 1^ \ 

Newton. Leibnitz, independent 
invention of differential cal- 
culus, 13 
' Nicholson and Carlisle, discov- 
ery <^i electrolysis, 1 1 1 . \\ 2 

Nollet, electrical hypothesis of, 
40, 41 

Non-electrical circuits, Watson's 

m)-i allc 

Non-electrics and electrics. Gil- 
bert's classification of, 22, 33 

•• n i I h ^iiion," Bacons, 

20 

o 

Occluded-gas process for fila- 
ment of incandescent elect! ic 
lamp. 150 

( lerste d's discovery, 142 

ited's discovery, Davy's 

communication of, to Royal 

ety, 1 j_\ 143 

Ohm's law, 157 

Ohm's mathematical dlsCOVCiy, 

first description of, 167, 
ohm's remarkable mathemat- 

i< al discovei v . 

11 v discharges, I Icrtz 

on. 
Oscillatory dii 

or, of lightning, ul 



196 



INDEX. 



Oscillatory discharge of Leyden 
jar, character of the magnet- 
ization produced by, 63 

Oxygen, independent discovery 
of, by Priestley and Scheele, 
13 



Page's dynamo - electric ma- 
chine, 155 

Page's electric motor, 158, 159 

Paine's electric light, 128-133 

Patent, Elkington's, date of, for 
electro-plating, 169 

Phenomena, dynamic, of the 
Leyden jar, Henry on, 61, 62 

Phial, Leyden, Cavallo on the 
invention of, 51, 52 

Phial, Leyden, invention of, by 
Cunaeus, 43, 44 

Phonograph, Edison's invention 
of, 164 

Phonograph, receiving dia- 
phragm of, 164 

Physiological effects of electric 
discharges of high frequency 
and potential, 57 

Physiological effects of Leyden 
jar, 47, 48 

Physiological effects of the dis- 
charge of a Leyden jar, Alla- 
mand on, 49 

Physiological effects of the dis- 
charge of a Leyden jar, early 
extravagant assertions as to 
the intensity of, 48 

Physiological effects of the dis- 
charge of a Leyden jar ; ex- 
periments at the convent of 
the Carthusians, 47 

Physiological effects of the dis- 
charge of a Leyden jar, Mu- 
schenbroeck on, 49 

Physiological effects of the dis- 
charge of a Leyden jar, Nol- 
let's experiments as to, 47, 
48 

Piccolomini, Bened.'ti, Galileo, 



independent discovery of the 
laws of motion by, 12 
Pile, Daniell's constant voltaic, 

135 

Pile, Volta's original description 
of, no 

Pixey's magneto-electric ma- 
chine, 154 

Plante's storage battery, 173 

Plating bath, 172 

Pliny, attractive nature of amber 
mentioned by, 22 

Polarization of voltaic cell, 139 

Possible future electrical inven- 
tions, 176, 178 

Power, electric, transmission of, 
advantages possessed by, 161, 
162 

Poynting on electric conduction, 
modern views as to the nature 

of, 74-79 
Priestley and Scheele, indepen- 
dent discovery of oxygen by, 

13 

Priestley on Du Fay's single-fluid 
electrical hypothesis, 37 

Priestley on invention of Leyden 
jar, 43 

Priestley on Richman's experi- 
ments, 84-86 

Process, carbonizing, for fila- 
ment of incandescent electric 
lamp, 156 

Process, occluded-gas, for fila- 
ment of incandescent electric 
lamp, 156 

Process of galvanoplastics, 171 

Pythagoras, anticipated by 
Thales, 16 



Radiation, electric, 68 

Reaumur, letter of Cunaeus to, 
concerning effects of dis- 
charge of Leyden jar, 47, 48 

Receiver, telephone, 164 

Receiving diaphragm of phono- 
graph, 164 



INDEX. 



197 



Regulation, self-, of electric 
motor, 160 

Reis, invention of the articulat- 
ing telephone by, 102, 103 

Researches, electrical, of Ste- 
phen Grey, 27, 28 

Researches, Faraday's experi- 
mental, 152, 153 

Resonance, acoustic, definition 
of, 67 

Resonance, use of term in phys- 
ical science, 67 

Richman's fatal experiments on 
atmospheric electricity, S4-S7 

Ritchie's dynamo-electric ma- 
chine, 154 

Ritchie's electric motor, 160 

Rods, lightning-, influence of 
sectional area on efficient ac- 
tion of, 100 

Royal Institution, Davy's exhi- 
bition of the carbon arc light 
at, 117 

Royal Society, announcement 
to, by Banks of the invention 
of the voltaic pile, 107-110 



Sapphires, diamonds, and other 
substances electrified by fric- 
tion, list of, 23 

Saxton's dynamo-electric ma- 
chine, 154 

Scheele and Priestley, indepen- 
dent discovery of oxygen by, 

13 

Schuylkill River, spirits fired by 
discharge of electricity across, 
by Franklin, 33 

Science, pure and applied, rela- 
tive merits of, 65 

Secondary battery, invention of, 

173 

Self-induction, influence of, on 
efficiency of lightning-rods, 

98 

Sensitive-thread discharge, Tes- 
te's, 56 



Ships, Harris on system of light- 
ning protection for, 87-89 

Siebeck's discovery of thermo- 
electricity, 165 

Silliman on Ampere's discov- 
ery, 143, 144 

Single-lluid electrical hypothe- 
sis, Franklin's, 38, 39 

Staite's electric arc light, 125- 
127 

Steady-current discharge of 
lightning, 91, 92 

Steinheil's claim as to the first 
conception of the electric tele- 
graph, 145 

Stephen Grey, electrical re- 
searches of, 27, 28 

Storage battery, charging of, 

175 
Storage battery, discharging of, 

175 
Storage battery, forming of 

plates of, 173 
Storage battery, invention of, 

173 
Storage battery, Faure, 176 
Storage battery, Plane's, 173 
Storage battery, probable fu- 
ture of, 176 
Streaming discharge, Tesla's, 

59 

Sturgeon's dynamo-electric ma- 
chine, 155 

Sturgeon's invention of the elec- 
tro-magnet, 135 

Sweigger's galvanic multiplier, 
136 

Sympathetic vibrations, 67 

Synchronous-multiplex telegra- 
phy, 152 



Telegraph, electric, inventions 
necessary to the completion 
of, I35 

Telegraph, electric, Morse's in- 
vention of, 145-147 

Telegraph, Morse system, im- 



198 



INDEX. 



portance of invention of Dan- 
iell's constant cell to, 139 

Telegraphy, contraplex, 151 

Telegraphy, diplex, 151 

Telegraphy, duplex, invention 
of, 150 

Telegraphy, harmonic, 152 

Telegraphy, multiplex, 152 

Telegraphy, synchronous-mul- 
tiplex, 152 

Telephone, articulating, inven- 
tion by Bell, 163 

Telephone, articulating, inven- 
tion of, by Reis, 162, 163 

Telephone, magneto-electric, 
163 

Telephone receiver, 164 

Telephone transmitter, 164 

Telephone, invention of, 165 

Tesla and Thomson, on the 
effects produced by rapidly 
alternating discharges of high 
• potential, 54 

Tesla's brush-and-spray dis- 
charge, 60 

Tesla's flaming discharge, 57 

Tesla's high-frequency dis- 
charge incandescent lamp, 59, 
60 

Tesla's sensitive-thread dis- 
charge, 56 

Tesla's streaming discharge, 59 

Thales, anticipated invention 
of Euclid's 47th proposition 
by, 16 

Thales' description of the nature 
of eclipses, 16 

Thales' division of the celestial 
sphere into five zones, 16 

Thales, first recorded experi- 
ment in electricity by, 16 

Thales of Miletus, 14-17 

Thales' original experiment, 
teachings of, 21 

Thales, some of the writings of, 
18 

Theophrastus, experiment of, 
19 



Thermo-electric current, Sie- 
beck's discovery of, 165 

Thermo-electricity, Siebeck's 
discovery of, 165 

Timely or mature inventions, 
10, 11 

Timely or mature inventions, 
influence of, 10, 11 

Tourmaline, electrification of, 
by friction, 19, 20 

Transformers, use of, 65 

Transmitter, telephone, 164 

Transmitting diaphragm of pho- 
nograph, 164 

Triangles, scalene and other, 
first investigated by Thales, 

15, 16 

Tunzelmann on Hertz's discov- 
eries, 68-70 

Turkey, electrocution of, 34 

U 

Unfruitful and untimely inven- 
tions, influence of, 9, 10 

Untimely and unfruitful inven- 
tions, 9, 10 

Untimely and unfruitful inven- 
tions, influence of, 9, 10 
V 

Vibrations, sympathetic, 67 

Vital fluid, supposed discovery 
of, by Galvani, 107 

Volta, investigations, 107-111 

Volta on the true cause of the 
phenomena observed in the 
experiments on frogs' legs, 
107, 108 

Volta's experiments with frogs' 
legs, 107 

Voltaic arc, intense heat of, 119 

Voltaic cell, polarization of, 139 

Voltaic pile, invention of, 107- 
110 

Von Kleist, invention of Ley- 
den jar by, 42 

Von Kleist's discovery, an- 
nouncement of, by Dr, Lie- 
berkuhn, 44-46 



INDEX. 



[ 99 



W 

Water, independent discovery 
of its composition by Caven- 
dish and Watt, 13 

Watson, experiments of, on 
electrical conducting power, 
20-31 

Watson on Muschenbroeck's 
experiments, 45-45 

Wats periments on elec- 

trical conducting power, 29- 

31 

Watson's experiments on elec- 
trical conducting power, con- 
clusions drawn from, 3 

Watson's so-called non-electri- 
cal circuits, 29, 30 

Watt and Cavendish, indepen- 



dent discovery of composition 
of water by. 13 

Waves, electro-magnetic, Hertz' 
conceptions of, 07 

Wheatstone's claim to priority 
of invention of the electric 
telegraph, 145 

Wheatstone's dynamo-electric 
machine, 155 

:e's dynamo-electric ma- 
chine, 155 

Wilde's electric motor. 160 

Wright's invention of electro- 
plating, 169 



Youmans on the birth of ideas, 
11, 12 






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thousand. 279 pages, 59 illustrations 2.50 

Central Station Book-keeping. With Sug- 
gested Forms. By H. A. Foster. (New) 2.50 

Continuous Current Dynamos and Mo- 
tors. An Elementary Treatise for Students. By 
Frank P. Cox, B. S. 271 pages, 83 illus 2.00 

Electricity at the Paris Exposition of 

1889. By Carl Hering. 250 pages, 62 illus .... 2.00 
Electric Lighting Specifications for the 

Use of Engineers and Architects. By E. A. Mer- 
rill. 175 pages 1.50 

The Q,uadruplex. By Wm. Mayer, Jr., and 
Minor M. Davis. With Chapters on the Dynamo 
in Relation to the Quadruplex, the Wheatstone 
Automatic Telegraph, etc. 126 pages, 63 illus 1.50 

The Elements of Static Electricity, with 
Full Descriptions of the Holtz and Topler Ma- 
chines. By Philip Atkinson, Ph.D. Second ed- 
ition, revised. 228 pages. 64 illus 1.50 

Lightning Flashes. A Volume of Short, Bright 
and Crisp Electrical Stories and Sketches. 160 
pages, copiously illustrated 1.50 



A Practical Treatise on Lightning Pro- 
tection. By \v. 11. Spang. 180 pages, 28 lllus.. 1.50 

A Practical Treatise <>n Lightning Con- 
ductors. By 11. w. Spang. 48 pages, 10 lllus.. 0.75 

Electricity and magnetism* Being a Si 
oi' Advanced Primers, By JL J. Houston, Ph. D. 
500 pages, 169 illustrations 1.00 

Electrical measurements and Other Ad- 
vanced Primers of Electricity. By E. .). 
Houston, pii.d. 429 pages, 169 lllus 1.00 

The Electrical Transmission of Intelli- 
gence, and Other Advanced Primers of 

Electricity. P.y E. J. Houston, Ph.D. 330 
pages, SS illustrations 1.00 

Electricity, One Hundred Years Ago and 
To-Day. By E. J. HOUSTON, Ph.D., 198 pages... 1.00 

Alternating Currents of Electricity. Their 
Generation, Measurement, Distribution and Ap- 
plication. By GlSBBBT Kapp. 176 pages, 38 illus. 1.00 

Recent Progress In Electric Railways. 
Being a Summary of Current Advance in Electric 
Railway Construction, Operation, Appliances, 
etc. Compiled by Carl Hering. 366 pgs.,110 illus. 1.00 

Davis' Standard Tables for Electric 
Wiremen. Fourth edition 1.00 

Reference Rook of Tables and Formula 
for Electric Street Railway Engineers. 
By E. A. Merrill 1.00 

Original Papers on Dynamo Machinery 
and Allied Subjects. Bv John Hopkinson, 
F. B.S. 249 pages, 90 illustrations 1.00 

I'niversal Wiring Computer for determin- 
t he sizes of Wires for Incandescent Electric| 
Lamp Leads without calculation, with Some 
Notes on Wiring, etc. By Carl IIering. 44 pgs. 1.00 

Dynamo and ?Fotor Ruildimr for Ama- 
teurs. With Working Drawings. By C. D. 
Parkdurst 1.00 

Experiments with Alternating Currents 
of Hi- li Potential and Hiirh Frequen- 
cy. By Nikola Tesla. 146 pages, 30 illus 1.00 

Lectures on the Electromagnet. By Prof. 

» anus P. Thompson. 2W pages, 75 illus l.oo 

Practical Information for Telephonists. 
By T. D. Lock wood. 19*2 pages 1.00 

Wheeler's Chart of AVire Gauges 100 

Wired Love ; A Romance of Dots and 
Dashes. 256 pages 0.75 

Tables of Equivalents of I nits of Meas- 
urements. By Carl Uering 0.50 



THIRD EDITION, JUST ISSUED. 

Revised. Enlarged. 

A DICTIONARY OF 

ELECTRICAL WORDS . 

TERMS # PHRASES. 



By EDWIN J. HOUSTON. A.M. 

GG9 Large Octavo Pages. 582 Illustrations. Price, $5.00. 

Some idea of the scope of this timely and important 

w ork and of the immense amount of labor involved in it, may- 
be formed when it is stated that it contains definitions of about 
5,000 Distinct Words, Terms or Phrases. 

The Dictionary is not a mere word book. The words, terms 
and phrases are invariably followed by a short* concise 
definition, giving the sense in which they are correctly em- 
ployed and a general statement of the principles of elec- 
trical science on which the definition is founded. 

As one feature, an elaborate system of cross references Las 
been adopted, so that it is as easy to find ilie definitions 

as the words, and aliases are readily detected and traced. 

The typography Is excellent, being large and bold, 
and so arranged that each word catches the eye at 

a glance by standing out in sharp relief from the page. 

Copies op the Dictionary, or of any other Electrical 
work published, will be mailed to any address in the 
world, postage prepaid, on receipt of price. Remit by P. O. 
Order, Draft, Registered Letter or Express and address : 

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353 BROADWAY, NEW YORK. 



ELECTRICITY AND MAGNETISM 

A Series of Advanced Primers, 

By Prof. EDWIN .1. HOUSTON, 

AUTHOR OF 

u A Dictionary of Electrical Words, Terms and Phrases." 

Cloth. NC|lgM 116 Illustrations. Trice, 1.00. 



Prof. Houston's Primers of Electricity written in 
1884 enjoyed a wide circulation, not only in the United 
States, but in Europe, and for sonic time have been out 
of print, i >wing to the great progress in electricity since 
that date the author has been Led to prepare an entirely 
new series of primers, but of a more advanced charac- 
ter in consonance with the advanced general knowl- 
edge ni electricity. 

Electricians will find these primers of marked inter- 
est from their lucid explanations of principles, and the 
general public will in them find an easily read and 
agreeable introduction to a fascinating subject. 



CONTENTS. 

I. — Effects of Electric Charge. II.— Insulators and 
Conductors. III. — Effects of an Electric Discharge. 
IV. — Electric Sources. V.— Electro-receptive De\ 
VI —Electric Current. VII.— Electric Units VIII. 
— Electric Work and Power. IX. — Varieties of Elec^ 
trie Circuits. X. — Magnetism. XI. — Magnetic Induc- 
tion. XII. — Theories of Magnetism. XIII. — Phenom- 
ena of the Earth's Magnetism. XIV, — Electro-Mag- 
XV. — Electrostatic Induction. XVI. — Frictional 
and Influence Machines. XVII — Atmospheric Elec- 
tricity. XVIII.— Voltaic Ceils. XIX.— Review, Prim- 
er of Prim 

PUBLISHED AND For. SALE BY 

The W. J. JOHNSTON COMPANY, Lt. 

333 BROADWAY, XKW YORK.. 



The Measurement of Electrical Currents 

And Otber Advanced Primers of Electricity. 

By Prof. Edwin J. Houston, A.M., 

AUTHOR OP 

"A Xfictionary of Electrical Words, Terms and Phrases" 

<&c, &c, &c. 

Cloth. 429 Pages. 160 Illustrations. Price, $1.00. 

This volume is the second of Prof. Houston's admir- 
able series of Advanced Primers of Electricity and is 
devoted to the measurement and practical applications 
of the electric current. 

Marked features of these books are the logical and 
lucid development of principles in language easily fol- 
lowed with no previous knowledge of electricity, and 
the abstracts from standard electrical authors at the 
end of each Primer, which in general have reference, 
and furnish an extension, to some point in the Primer, 
and at the same time give the reader an introduction to 
electrical literature. 



OOINTTEHXTTS- 

I. The Measurement of Electric Currents. II. The 
Measurement of Electromotive Force. III. The Meas- 
urement of Electric Resistances. IV. Voltaic Cells. 

V. Thermo-Electric Cells and Other Electric Sources. 

VI. The Distribution of Electricity by Constant Cur- 
rents. VII. Arc Lighting. VIII. Incandescent Elec- 
tric Lighting. IX. Alternating Currents. X. Alter- 
nating Current Distribution. XI. Electric Currents of 
High Frequency. XII. Electro-Dynamic Induction. 
XIII. Induction Coils and Transformers. XIV. Dy- 
namo Electric Machines. XV. Electro - Dynamics. 
XVI. The Electro-Motor. XVII. The Electric Trans- 
mission of Power. XVIII. Review : Primer of Primers. 

Published and for sale by 

The W. J. JOHNSTON COMPANY, Lt. 

353 BROADWAY, NEW YORK. 



r THE 

Electrical Transmission of Intelligence 

/frjd Other Advanced Primers of Electricity 
BY PROF. EDWIN J, HOUSTON, A.M., 

Author of 

"A Dictionary of Electrical Words, Terms and PI/ rases, 7 * 
<£c. y dto, $ d'C. 



CLOTH. PRICE, Sl.OO. 



The third and concluding volume of Prof. Houston's 
Series of Advanced Primers of Electricity is devoted to 
the telegraph, telephone, and miscellaneous applica- 
tions of the electric current. 

In this volume the difficult subjects of multiple and 
cable telegraphy and electrolysis, as well as the tele- 
phone, storage battery, etc., are treated in a manner 
that enables the beginner to easily grasp the principles, 
and yet with no sacrifice iu completeness of presenta- 
tion. 

CONTENTS 

T. The Electric Transmission of Intelligence. II. 
The Electric Telegraph. III. Multiple Telegraphy. 
IV. Cable Telegraphy. V. Electric Annunciators and 
Alarms. VI. Time Telegraphy. VII. The Telephone. 
VIII Electrolysis. IX. Electro-Metallurgy. X. stor- 
<r Secondary Batteries. XI. Electricity in War- 
fun-; Electric Welding. XII. Some Other Applications 
ol Electricity. XIII. Electro-Therapeutics. XIV. 
Review, Primers of Primers. 

PUBLISHED AND Foil SALE BY 

The W. J. JOHNSTON COMPANY, Lt. 

5433 BROADWAY, NEiW YORK, 



THE ELECTRIC MOTOR 

AND ITS APPLICATIONS. 



By T. C. Martin and Joseph Wetzlcr, with aa 

appendix bringing the book down to 

date by Dr. Louis Bell. 



Affl 325 Large Quarto Pago*, and Jfe ft 

^■J 354 Illustrations. PRICE, Vv 

JfkJ ^ postage prepaid to ;ny aft. I 

t^P|J part of tlie World* *j/" 



This timely work is the first American Book on 
Electric Motors, and the only book in any lan- 
guage dealing exclusively and fully with the 
modern Electric Motor in all its various practical 
applications. The book is a handsome quarto, 
the page being of the same size as Dredge's large 
work on "Electric Illumination/' and many of 
Cue cuts are full-page. 

No effort has been spared to make the book 
complete to date, and it will prove invaluable to 
every one interested in the progress and develop- 
ment of the Electric Motor or the Electrical 
Transmission of Energy. 

Copies of tliis or any other electrical book pub- 
lished, will be mailed to any address in the world, 
postage prepaid, on receipt of price. Address 

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353 BROADWAY, NEW YORK. 



The Electric Railway 

IN THEORY AND PRACTICE. ' 

r.yO.T. CROSBY and Dr. LOUIS BELL, 
Second Edition, liaised and Enlarged. 

416 Octavo Pages, 1S2 Illus. Price, $2 50 

IMi is the first 8YSTBM ITIC 1 U I A I I s r that has 

been published oh the I I I < l li I ( li A I I II .11". <//«</ 
U is intended to cover t)i> (. 1 :.\ / ."/; li li:i.\- 
Ciriis OF />/>/<. \. CONSTRUC- 
TION A \ l> on i: A I IO> . 



TABLE OK CONTEKTSl 

Chapter I. General Electrical Theory. 

II. Prime M< 

III. Motors and Car Equipment. 

11 IV. The Line. 

V. Track, Car Houses, Snow Machines. 

4i VI. The Station. 

M VII. The Efficiency of Electric Traction. 

" VIII. S attery Traction. 

lk IX. Miscellaneous Methods of Electric Traction. 

il X. High Speed Service. 

XI Commercial Considerations. 

XII. Historical X : 

APPENDICES: 

Appendix A. Electric Railway vs. Telephone Decisions. 

B. Instiuctions to Linemen. 

C. Engineer's Log Book. 

I). Classification of Expenditures of Electric Street 
Rail M 
Concerning Lightning Protection, by Prof. 
Elihu Thomson. 
F. Mol rs with Beveled Gear, and Series Multiple 
Control of Motors. 
44 G. Meth 'd of Measuring Insulation Resistance 

t rhead Lb 



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PRINCIPLES OP 

DYNAMO ELEGTRIG MACHINES 

AND 

Practical Directions for Designing 
and Constructing Dynamos, 

By CARL HERING. 
Sixth Thousand. 279 pages. 59 illustrations. Price, $2.40. 



CONTENTS. 

Review of Electrical Units and Fundamental Laws. 

Fundamental Principles of Dynamos and Motors. 

Magnetism and Electromagnetic Induction. 

Generation of Electromotive Force in Dynamos* 

Armatures. 

Calculation of Armatures. 

Field Magnet Frames. 

Field Magnet Coils. 

Regulation of Machines. 

Examining Machines. 

Practical Deductions from the Franklin Institute Tests 

of Dynamos. 
The So-called "Dead Wire" on Gramme Armatures. 
Explorations of Magnetic Fields Surrounding Dynamos. 
Systems of Cylinder-Armature Windings. 
Table of Equivalents of Units of Measurements. 



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353 BROADWAY, NEW YORJK. 



Electricity at lie Paris Exposition 



OF 1889. 



By CARL HERING. 

Author of "Prim iptes of Dynamo- l.leetric Machines" 

•• accent "Progress in VSleetrie Railways," *• ( niversal 

Wiring Computer," " To hies of Equivalents of 

I nits of Measur em ents, &c. 



Cloth. Large Octavo. 250 pages, 62 Illustrations. Price, $2.00. 

This work contains a general description of the more 
important exhibits at the Paris Exposition of 1889, accom- 
panied by comparisons, opinions, histories of their develop- 
ment, summaries of the progress shown, statistics, and in 
general such information as would indicate the state of the 
art at that time. Also, an account of the work of the Inter- 
national Congress of Electricians which met during the 
Exposition. 

CONTENTS, 

Introduction, including work of the International Elec- 
trical Congress. — I. Electro-Dynamics, including electric 
lighting, dynamos, power, etc. — II. Telegraphy and Tele- 
phony. — III. Annunciators, Alarms, Bells, Clocks, Gas 
Lighting, etc. and Miscellaneous Applications of Electricity, 
IV. Electro-Chemistry, including primary and secondary 
batteries. — V, Electrical Measuring Instruments and Scien- 
tific Apparatus. — VI. Thermo Generators. — VII. Wires, 
Cables, and Conduits. — VIII. Applications of Electricity 
in Medicine and Surgery. — IX. Miscellaneous Exhibits. — 
X. General Supplies. 

PUBLISHED AND FOR SALE BY 

The W. J. JOHNSTON COMPANY, Lt. 

J4.VJ BROADWAY, NEW YORK. 



RECENT PROGRESS 



IN 



ELECTRIC RAILWAYS 

BEING A SUMMARY OF CURRENT PROGRESS 

IN ELECTRIC RAILWAY CONSTRUCTION, 

OPERATION, SYSTEMS, MACHINERY, 

APPLIANCES, &c, COMPILED 

By CARL HERING. 

386 pages and 120 illustrations. Cloth, • Price, $1.00 



This volume contains a classified summary of the 
recent literature on this active and promising branch 
of electrical progress, with descriptions of new appa- 
ratus and devices of general interest. 



CONTENTS. 

Chapter I.— Historical. Chapter II. — Development 
and Statistics. Chapter III. — Construction and Opera- 
tion. Chapter IV. — Cost of Construction and Opera- 
tion. Chapter V. — Overhead Wire Surface Roads. 
Chapter VI. — Conduit and Surface Conductor Roads. 
Chapter VII. — Storage Battery Roads. Chapter VIII. 
— Underground Tunnel Roads. Chapter IX. -High 
Speed Interurban Railroads. Chapter X.— Miscellan- 
eous Systems. Chapter XL— Generators, Motors and 
Trucks. Chapter XII. — Accessories. 

Copies of this or any other electrical book or books pub- 
lished, will be promptly mailed to any address in the world, 
postage prepaid, on receipt of price. Address 

The W. J. JOHNSTON COMPANY, Lt. 

353 BROADWAY, NEW YORK. 



Jus t Publi shed. 

Continuous Curat Dynamos k Motors. 

Their Tlieory, Design and Testing. 

With Sections on Indicator Diagrams. Properties 
of Saturated Steam, Belting Calculations, Etc. 

AN ELEMENTARY TREATISE FOR STUDENTS. 



By Frank P. Cox, B. S. 



Cloth, 271 Pages, 83 Illustrations, Price $2.00. 

The purpose of this work is to present to students of electro- 
technics in a simple and direct manner, without the use of higher 
mathematics, the theory, design and testing of^ continuous current 
dynamos and motors as understood and carried out in commer- 
cial practice. 

luable feature of the work is the application to numeri- 
cal problems of the principles developed, the problems being so 
selected as to cover as broad a held as possible and to show how 
to make the various compromises always found necessary in 
practical designing. 

Owing to the steam engine being so closely allied to the 
testing and operation of d.namos and motors, sections on indi - 
cator diagrams, steam power calculations and belting are included. 

CONTENTS. 

Chapter I. — The Absolute System of Measurement. 
II. — Electro-Magnetic Induction. III. — Classification of Ma- 
chines and General Principles of the Magnetic Circuit. IV. — The 
Dynamo as a Motor. V. — Calculations Pertaining to the Mag. 
netic Circuit. VI. — Theory of Windings, I sses, etc. VII. — 
The Dynamo Considered as a Motor VIII — I ►esign of Anna- 
tures. IX. — ! nets. X — Design of Motors. 

XI — Dynamo and M< ag. XII. — Erricier. 

XII I. — Indicator Diagrams. XIV. — Steam Engine Calculations 
APPBNDlx I. — Te-ts of Iron. II. — Ampere turn Ta 

III — Determination of Sizes of Wire for Armatures and Field 
Coils. IV — Pelting. 

PUBLISH / /> AWn ron s l/.i: i:y 

The W. J. JOHNSTON COMPANY, Lt. 

333 BROADWAY, NEW YORK. 



SECOND EDITION, BEVISED. 
ELEMEHTS OF 

STATIC ELECTRICITY, 

WITH FULL DESCRIPTION OF THE HOLTZ AND TOPLER 
MACHINES AND THEIR MODE OF OPERATION. 

By PHILIP ATKINSON, A.M., Ph.D.> 



Cloth, 12mo; 228 Pages; ^Illustrations. 

:f>:e=lxo:e], - slso. 

POSTAGE to any part of the world PREPAID. 



The author of this treatise has made a special study 
of Static Electricity, and is an acknowledged master 
of the subject. The book embodies the result oi 
much original investigation and experiment, which, 
Dr. Atkinson's long experience as a teacher enables 
him to describe in clear and interesting language, 
devoid of technicalities. 

The principles of electricity are presented untram- 
meled, as far as possible, by mathematical formulae, 
so as to meet the requirements of a large class who 
have not the time or opportunity to master the in- 
tricacies of formulae, which are usually so perplexing 
to all but expert mathematicians. 

The views expressed in the book are the result of 
many years' experience in the class room, the lectura 
room and the laboratory, and were adopted only 
after the most rigid test of actual and oft-repeated 
experiment by the author. 

Copies oftliis or any otlier electrical look pnh~ 
lislied, will be mailed to any address in the world, 
postage prepaid, on receipt of price. Address 

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Alternating Currents of Electricity : 

Their Generation, Measurement, Distribution 
and Application. 



By Gi short Kapp, M.I.C.E., MI.EE. 

With an Introduction by William Stanley, Jr. 



Cloth. 164 Pages, 37 Illus., 2 Plates. $1.00. 

This volume explains in clear, simple language the 
theory of alternating currents and apparatus, particular 
attention bring paid to transformers and multi-phase 
currents and motors. 

The treatment is entirely a practical one. the descrip- 
tions noting the various advantages and defects of dif- 
ferent types, and the sections devoted to designing 
containing the practical data and instructions required 
by tiie engineer. 

CONTENTS. 

Introduction, by William Stanley, Jr. Chap. I. In- 
y. Chap. II. If< isurement of Pressure, Cur- 
rent and Power. Chap. III. Conditions of Maximum 
p. IV. Alternating Current Machines. 
p. V. .Mechanical Construction of Alternators, 
p. VI. Description of B i e Alternators. Chap. 
VII. Transformers. Chap. VIII. Central Stations and 
Distribution of Power, chap. IX. Examples of Cen- 
tral Stations. \. Parallel Coupling of Alterna- 
Chap. XI. Alternating Current Motors. Chap. 
XII. S< if-Starting Motors. Chap. XIII. Multi-phase 
Currents. 

PUBLISHED AND FOR SALE BY 

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333 BROADWAY, NEW YORK:. 



Dynamo and Motor Building 

FOR /\A\ATEURS. 

WITH WORKING DRAWINGS. 



BY 
LIEUT. C. D. PARKHURST, U. S. A. 

Cloth, 163 pages. 71 Illustrations. Price, $1.00. 



Descriptions and working drawings are given of the 
following dynamos and motors : 

A small ventilating fan motor. — A sewing machine 
battery motor, requiring no patterns or castings in its con 
struction. — A sewing machine motor of more finished 
appearance and greater efficiency than the above. — A 50- 
light incandescent dynamo. 

A chapter treats of armature windings, connections 
and currents, giving minute instructions illustrated with de- 
tailed drawings. In the chapter on the 50-light dynamo the 
various technical points involved in dynamo design are fully 
and clearly treated, enabling the amateur to design other 
forms of machines than those described, in which he will be 
assisted by an appendix giving data of a number of high 
class motors aud dynamos of standard manufacture. 

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EXPERIMENTS WITH 

Alternate Gurrents 

Of High Potential and High Frequency. 

11} NIKOLA TIM. A. 



156 pages, with Portrait and 35 Illustrations. 
Cloth, $1.00. 



This book gives in full Mr. Tesla's important lecture 
before the London Institution of Electrical Engineers, 
which embodies the results of years of patient study 
oiid investigation on Mr. Tesla's part of the phenomena 
of Alternating Currents of Enormously High Fre- 
quency and Electromotive Force. 

EVERY ELECTRICIAN, ELECTRICAL ENGINEER OR 
STUDENT OF ELECTRICAL PHENOMENA WHO MAKES 
ANY PRETENSIONS TO THOROUGH ACQUAINTANCE 
WITH RECENT PROGRESS IN THIS IMPORTANT FIELD 
OF RESEARCH WHICH MR TESLA HAS SO ABLY DE- 
VELOPED MIST READ AND REREAD THIS LECTURE. 

The book is well illustrated with 35 cuts of Mr. 
Tenia's experimental apparatus, and contains in ad- 
dition a biographical sketch, accompanied by a full- 
page portrait, which forms a fitting frontispiece to a 
ire which created such widespread interest. 

pies of this or any other electrical book or books pub- 
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THE PIONEER ELECTRICAL JOURNAL OF AMERICA. 




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most widely circulated electrical journal 

In tlie world* 

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trician anxious to rise in his profession, but by every 
intelligent American. 

The paper is ably edited and noted for explaining 
electrical principles and describing new inventions and 
discoveries in simple and easy language, devoid of 
technicalities. It also gives promptly the most com- 
plete news from all parts of the world, relating to the 
different applications of electricity. 



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